
Type: LanguageSpecification

Status: Active

Resolution: Unresolved

Labels:None

Impact:Unknown 'null' severity

Likelihood:Unknown 'null' severity
Using the same value on either side of a binary operator is almost always a mistake. In the case of logical operators, it is either a copy/paste error and therefore a bug, or it is simply wasted code, and should be simplified. In the case of bitwise operators and most binary mathematical operators, having the same value on both sides of an operator yields predictable results, and should be simplified.
Note that this rule will raise issues on a == a and a != a expressions which are sometime used to detect NaN values. It is recommended to use instead math.isnan or an equivalent function. This will improve code readability.
Noncompliant Code Example
if a == a: # Noncompliant work() if a != a: # Noncompliant work() if a == b and a == b: # Noncompliant work() if a == b or a == b: # Noncompliant work() j = 5 / 5 # Noncompliant k = 5  5 # Noncompliant
Exceptions
The following are ignored:
 The expression 1 << 1