Cyclomatic complexity is too high in method populate. (6) Open
def populate(self, options=None):
skip_empty = not config.app.registry.get(
'display_artist_without_album', to='bool')
for data in self.data['artists']['items']:
if skip_empty and data['albums_count'] < 1:- Read upRead up
- Exclude checks
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:
| Construct | Effect on CC | Reasoning |
|---|---|---|
| if | +1 | An if statement is a single decision. |
| elif | +1 | The elif statement adds another decision. |
| else | +0 | The else statement does not cause a new decision. The decision is at the if. |
| for | +1 | There is a decision at the start of the loop. |
| while | +1 | There is a decision at the while statement. |
| except | +1 | Each except branch adds a new conditional path of execution. |
| finally | +0 | The finally block is unconditionally executed. |
| with | +1 | The with statement roughly corresponds to a try/except block (see PEP 343 for details). |
| assert | +1 | The assert statement internally roughly equals a conditional statement. |
| Comprehension | +1 | A list/set/dict comprehension of generator expression is equivalent to a for loop. |
| Boolean Operator | +1 | Every boolean operator (and, or) adds a decision point. |
Function populate has a Cognitive Complexity of 7 (exceeds 5 allowed). Consider refactoring. Open
def populate(self, options=None):
skip_empty = not config.app.registry.get(
'display_artist_without_album', to='bool')
for data in self.data['artists']['items']:
if skip_empty and data['albums_count'] < 1:- Read upRead up
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
Similar blocks of code found in 5 locations. Consider refactoring. Open
return True if len(self.data['artists']['items']) > 0 else False- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 33.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Missing whitespace after ',' Open
cache = artist.fetch(helper.TreeTraverseOpts(lvl=3,noRemote=True))- Read upRead up
- Exclude checks
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'}]Expected 2 blank lines, found 1 Open
class Node_similar_artist(INode):- Read upRead up
- Exclude checks
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