comparison_to_true.rst

Comparing things to True the wrong way

Per the PEP 8 Style Guide, the preferred ways to compare something to True are the patterns if cond is True: or if cond:. This is only a guideline. It can be ignored if needed. But the purpose of the PEP 8 Style Guide is to improve the readability of code.

Example

The statement below uses the equality operator to compare a boolean variable to True. This is not the PEP 8 preferred approach to comparing values to True.

flag = True

if flag == True:  # Not PEP 8's preferred pattern
    print "This works, but is not the preferred PEP 8 pattern for comparing values to True"

Solutions

Compare values to True using the pattern if cond is True:

The code below uses the PEP 8 preferred pattern of if cond is True:.

flag = True

if flag is True:
    print "PEP 8 Style Guide prefers this pattern"

Compare values to True using the pattern if cond is True:

The code below uses the PEP 8 preferred pattern of if cond:. This only works if the object, variable, or expression evaluates to a Boolean value of True or False.

flag = True

if flag:
    print "PEP 8 Style Guide prefers this pattern"

References

• pep8 - E712
• PEP 8 Style Guide - Progrmaming Recommendations