ComplianceAsCode/content

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

• Cognitive Complexity

Merging collapsible if statements increases the code's readability.

Noncompliant Code Example

if condition1:
    if condition2:
        # ...

Compliant Solution

if condition1 and condition2:
    # ...

Having two branches in the same if structure with the same implementation is at best duplicate code, and at worst a coding error. If the same logic is truly needed for both instances, then they should be combined.

Noncompliant Code Example

if 0 <= a < 10:
    do_the_thing()
elif 10 <= a < 20:
    do_the_other_thing()
elif 20 <= a < 50:
    do_the_thing()  # Noncompliant; duplicates first condition
else:
    do_the_rest()

b = 4 if a > 12 else 4

Compliant Solution

if (0 <= a < 10) or (20 <= a < 50):
    do_the_thing()
elif 10 <= a < 20:
    do_the_other_thing()
else:
    do_the_rest()

b = 4

or

if 0 <= a < 10:
    do_the_thing()
elif 10 <= a < 20:
    do_the_other_thing()
elif 20 <= a < 50:
    do_the_third_thing()
else:
    do_the_rest()

b = 8 if a > 12 else 4

Having two branches in the same if structure with the same implementation is at best duplicate code, and at worst a coding error. If the same logic is truly needed for both instances, then they should be combined.

Noncompliant Code Example

if 0 <= a < 10:
    do_the_thing()
elif 10 <= a < 20:
    do_the_other_thing()
elif 20 <= a < 50:
    do_the_thing()  # Noncompliant; duplicates first condition
else:
    do_the_rest()

b = 4 if a > 12 else 4

Compliant Solution

if (0 <= a < 10) or (20 <= a < 50):
    do_the_thing()
elif 10 <= a < 20:
    do_the_other_thing()
else:
    do_the_rest()

b = 4

or

if 0 <= a < 10:
    do_the_thing()
elif 10 <= a < 20:
    do_the_other_thing()
elif 20 <= a < 50:
    do_the_third_thing()
else:
    do_the_rest()

b = 8 if a > 12 else 4

A long parameter list can indicate that a new structure should be created to wrap the numerous parameters or that the function is doing too many things.

Noncompliant Code Example

With a maximum number of 4 parameters:

def do_something(param1, param2, param3, param4, param5):
    ...

Compliant Solution

def do_something(param1, param2, param3, param4):
    ...