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:
