Cyclomatic Complexity

Cyclomatic Complexity corresponds to the number of decisions a block of code contains plus 1. This number (also called McCabe number) is equal to the number of linearly independent paths through the code. This number can be used as a guide when testing conditional logic in blocks.

Radon analyzes the AST tree of a Python program to compute Cyclomatic Complexity. Statements have the following effects on Cyclomatic Complexity:

Source: http://radon.readthedocs.org/en/latest/intro.html

Cyclomatic Complexity

Cyclomatic Complexity corresponds to the number of decisions a block of code contains plus 1. This number (also called McCabe number) is equal to the number of linearly independent paths through the code. This number can be used as a guide when testing conditional logic in blocks.

Radon analyzes the AST tree of a Python program to compute Cyclomatic Complexity. Statements have the following effects on Cyclomatic Complexity:

Source: http://radon.readthedocs.org/en/latest/intro.html

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Separate top-level function and class definitions with two blank lines.

Method definitions inside a class are separated by a single blank
line.

Extra blank lines may be used (sparingly) to separate groups of
related functions.  Blank lines may be omitted between a bunch of
related one-liners (e.g. a set of dummy implementations).

Use blank lines in functions, sparingly, to indicate logical
sections.

Okay: def a():\n    pass\n\n\ndef b():\n    pass
Okay: def a():\n    pass\n\n\nasync def b():\n    pass
Okay: def a():\n    pass\n\n\n# Foo\n# Bar\n\ndef b():\n    pass
Okay: default = 1\nfoo = 1
Okay: classify = 1\nfoo = 1

E301: class Foo:\n    b = 0\n    def bar():\n        pass
E302: def a():\n    pass\n\ndef b(n):\n    pass
E302: def a():\n    pass\n\nasync def b(n):\n    pass
E303: def a():\n    pass\n\n\n\ndef b(n):\n    pass
E303: def a():\n\n\n\n    pass
E304: @decorator\n\ndef a():\n    pass
E305: def a():\n    pass\na()
E306: def a():\n    def b():\n        pass\n    def c():\n        pass

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Separate inline comments by at least two spaces.

An inline comment is a comment on the same line as a statement.
Inline comments should be separated by at least two spaces from the
statement. They should start with a # and a single space.

Each line of a block comment starts with a # and a single space
(unless it is indented text inside the comment).

Okay: x = x + 1  # Increment x
Okay: x = x + 1    # Increment x
Okay: # Block comment
E261: x = x + 1 # Increment x
E262: x = x + 1  #Increment x
E262: x = x + 1  #  Increment x
E265: #Block comment
E266: ### Block comment

Separate top-level function and class definitions with two blank lines.

Method definitions inside a class are separated by a single blank
line.

Extra blank lines may be used (sparingly) to separate groups of
related functions.  Blank lines may be omitted between a bunch of
related one-liners (e.g. a set of dummy implementations).

Use blank lines in functions, sparingly, to indicate logical
sections.

Okay: def a():\n    pass\n\n\ndef b():\n    pass
Okay: def a():\n    pass\n\n\nasync def b():\n    pass
Okay: def a():\n    pass\n\n\n# Foo\n# Bar\n\ndef b():\n    pass
Okay: default = 1\nfoo = 1
Okay: classify = 1\nfoo = 1

E301: class Foo:\n    b = 0\n    def bar():\n        pass
E302: def a():\n    pass\n\ndef b(n):\n    pass
E302: def a():\n    pass\n\nasync def b(n):\n    pass
E303: def a():\n    pass\n\n\n\ndef b(n):\n    pass
E303: def a():\n\n\n\n    pass
E304: @decorator\n\ndef a():\n    pass
E305: def a():\n    pass\na()
E306: def a():\n    def b():\n        pass\n    def c():\n        pass

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Separate top-level function and class definitions with two blank lines.

Method definitions inside a class are separated by a single blank
line.

Extra blank lines may be used (sparingly) to separate groups of
related functions.  Blank lines may be omitted between a bunch of
related one-liners (e.g. a set of dummy implementations).

Use blank lines in functions, sparingly, to indicate logical
sections.

Okay: def a():\n    pass\n\n\ndef b():\n    pass
Okay: def a():\n    pass\n\n\nasync def b():\n    pass
Okay: def a():\n    pass\n\n\n# Foo\n# Bar\n\ndef b():\n    pass
Okay: default = 1\nfoo = 1
Okay: classify = 1\nfoo = 1

E301: class Foo:\n    b = 0\n    def bar():\n        pass
E302: def a():\n    pass\n\ndef b(n):\n    pass
E302: def a():\n    pass\n\nasync def b(n):\n    pass
E303: def a():\n    pass\n\n\n\ndef b(n):\n    pass
E303: def a():\n\n\n\n    pass
E304: @decorator\n\ndef a():\n    pass
E305: def a():\n    pass\na()
E306: def a():\n    def b():\n        pass\n    def c():\n        pass

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Separate top-level function and class definitions with two blank lines.

Method definitions inside a class are separated by a single blank
line.

Extra blank lines may be used (sparingly) to separate groups of
related functions.  Blank lines may be omitted between a bunch of
related one-liners (e.g. a set of dummy implementations).

Use blank lines in functions, sparingly, to indicate logical
sections.

Okay: def a():\n    pass\n\n\ndef b():\n    pass
Okay: def a():\n    pass\n\n\nasync def b():\n    pass
Okay: def a():\n    pass\n\n\n# Foo\n# Bar\n\ndef b():\n    pass
Okay: default = 1\nfoo = 1
Okay: classify = 1\nfoo = 1

E301: class Foo:\n    b = 0\n    def bar():\n        pass
E302: def a():\n    pass\n\ndef b(n):\n    pass
E302: def a():\n    pass\n\nasync def b(n):\n    pass
E303: def a():\n    pass\n\n\n\ndef b(n):\n    pass
E303: def a():\n\n\n\n    pass
E304: @decorator\n\ndef a():\n    pass
E305: def a():\n    pass\na()
E306: def a():\n    def b():\n        pass\n    def c():\n        pass

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace around keywords.

Okay: True and False
E271: True and  False
E272: True  and False
E273: True and\tFalse
E274: True\tand False

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Separate top-level function and class definitions with two blank lines.

Method definitions inside a class are separated by a single blank
line.

Extra blank lines may be used (sparingly) to separate groups of
related functions.  Blank lines may be omitted between a bunch of
related one-liners (e.g. a set of dummy implementations).

Use blank lines in functions, sparingly, to indicate logical
sections.

Okay: def a():\n    pass\n\n\ndef b():\n    pass
Okay: def a():\n    pass\n\n\nasync def b():\n    pass
Okay: def a():\n    pass\n\n\n# Foo\n# Bar\n\ndef b():\n    pass
Okay: default = 1\nfoo = 1
Okay: classify = 1\nfoo = 1

E301: class Foo:\n    b = 0\n    def bar():\n        pass
E302: def a():\n    pass\n\ndef b(n):\n    pass
E302: def a():\n    pass\n\nasync def b(n):\n    pass
E303: def a():\n    pass\n\n\n\ndef b(n):\n    pass
E303: def a():\n\n\n\n    pass
E304: @decorator\n\ndef a():\n    pass
E305: def a():\n    pass\na()
E306: def a():\n    def b():\n        pass\n    def c():\n        pass

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Separate inline comments by at least two spaces.

An inline comment is a comment on the same line as a statement.
Inline comments should be separated by at least two spaces from the
statement. They should start with a # and a single space.

Each line of a block comment starts with a # and a single space
(unless it is indented text inside the comment).

Okay: x = x + 1  # Increment x
Okay: x = x + 1    # Increment x
Okay: # Block comment
E261: x = x + 1 # Increment x
E262: x = x + 1  #Increment x
E262: x = x + 1  #  Increment x
E265: #Block comment
E266: ### Block comment

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

When catching exceptions, mention specific exceptions when possible.

Okay: except Exception:
Okay: except BaseException:
E722: except:

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Separate top-level function and class definitions with two blank lines.

Method definitions inside a class are separated by a single blank
line.

Extra blank lines may be used (sparingly) to separate groups of
related functions.  Blank lines may be omitted between a bunch of
related one-liners (e.g. a set of dummy implementations).

Use blank lines in functions, sparingly, to indicate logical
sections.

Okay: def a():\n    pass\n\n\ndef b():\n    pass
Okay: def a():\n    pass\n\n\nasync def b():\n    pass
Okay: def a():\n    pass\n\n\n# Foo\n# Bar\n\ndef b():\n    pass
Okay: default = 1\nfoo = 1
Okay: classify = 1\nfoo = 1

E301: class Foo:\n    b = 0\n    def bar():\n        pass
E302: def a():\n    pass\n\ndef b(n):\n    pass
E302: def a():\n    pass\n\nasync def b(n):\n    pass
E303: def a():\n    pass\n\n\n\ndef b(n):\n    pass
E303: def a():\n\n\n\n    pass
E304: @decorator\n\ndef a():\n    pass
E305: def a():\n    pass\na()
E306: def a():\n    def b():\n        pass\n    def c():\n        pass

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Surround operators with a single space on either side.

- Always surround these binary operators with a single space on
  either side: assignment (=), augmented assignment (+=, -= etc.),
  comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
  Booleans (and, or, not).

- If operators with different priorities are used, consider adding
  whitespace around the operators with the lowest priorities.

Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]

E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E225: z = 1and 1
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Use indent_size (PEP8 says 4) spaces per indentation level.

For really old code that you don't want to mess up, you can continue
to use 8-space tabs.

Okay: a = 1
Okay: if a == 0:\n    a = 1
E111:   a = 1
E114:   # a = 1

Okay: for item in items:\n    pass
E112: for item in items:\npass
E115: for item in items:\n# Hi\n    pass

Okay: a = 1\nb = 2
E113: a = 1\n    b = 2
E116: a = 1\n    # b = 2

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Each comma, semicolon or colon should be followed by whitespace.

Okay: [a, b]
Okay: (3,)
Okay: a[1:4]
Okay: a[:4]
Okay: a[1:]
Okay: a[1:4:2]
E231: ['a','b']
E231: foo(bar,baz)
E231: [{'a':'b'}]

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Limit all lines to a maximum of 79 characters.

There are still many devices around that are limited to 80 character
lines; plus, limiting windows to 80 characters makes it possible to
have several windows side-by-side.  The default wrapping on such
devices looks ugly.  Therefore, please limit all lines to a maximum
of 79 characters. For flowing long blocks of text (docstrings or
comments), limiting the length to 72 characters is recommended.

Reports error E501.

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Don't use spaces around the '=' sign in function arguments.

Don't use spaces around the '=' sign when used to indicate a
keyword argument or a default parameter value, except when
using a type annotation.

Okay: def complex(real, imag=0.0):
Okay: return magic(r=real, i=imag)
Okay: boolean(a == b)
Okay: boolean(a != b)
Okay: boolean(a <= b)
Okay: boolean(a >= b)
Okay: def foo(arg: int = 42):
Okay: async def foo(arg: int = 42):

E251: def complex(real, imag = 0.0):
E251: return magic(r = real, i = imag)
E252: def complex(real, image: float=0.0):

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x

Avoid extraneous whitespace.

Avoid extraneous whitespace in these situations:
- Immediately inside parentheses, brackets or braces.
- Immediately before a comma, semicolon, or colon.

Okay: spam(ham[1], {eggs: 2})
E201: spam( ham[1], {eggs: 2})
E201: spam(ham[ 1], {eggs: 2})
E201: spam(ham[1], { eggs: 2})
E202: spam(ham[1], {eggs: 2} )
E202: spam(ham[1 ], {eggs: 2})
E202: spam(ham[1], {eggs: 2 })

E203: if x == 4: print x, y; x, y = y , x
E203: if x == 4: print x, y ; x, y = y, x
E203: if x == 4 : print x, y; x, y = y, x