Cyclomatic complexity is too high in function merge_json_args. (11) Open
def merge_json_args(parser, args, json_data=None):
def filter_conflict_args(l1, l2):
# l2 args got priority on l1
l1 = copy.copy(l1)
l2 = copy.copy(l2)
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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 merge_json_args
has a Cognitive Complexity of 16 (exceeds 5 allowed). Consider refactoring. Open
def merge_json_args(parser, args, json_data=None):
def filter_conflict_args(l1, l2):
# l2 args got priority on l1
l1 = copy.copy(l1)
l2 = copy.copy(l2)
- 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
Refactor this function to reduce its Cognitive Complexity from 20 to the 15 allowed. Open
def merge_json_args(parser, args, json_data=None):
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Cognitive Complexity is a measure of how hard the control flow of a function is to understand. Functions with high Cognitive Complexity will be difficult to maintain.
See
Rename field "parser" Open
parser = None
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It's confusing to have a class member with the same name (case differences aside) as its enclosing class. This is particularly so when you consider the common practice of naming a class instance for the class itself.
Best practice dictates that any field or member with the same name as the enclosing class be renamed to be more descriptive of the particular aspect of the class it represents or holds.
Noncompliant Code Example
class Foo: foo = '' def getFoo(self): ... foo = Foo() foo.getFoo() # what does this return?
Compliant Solution
class Foo: name = '' def getName(self): ... foo = Foo() foo.getName()