Do python single line comments have to obey indentation/whitespace rules?

Question

If I have python code that requires indenting (for, with, function, etc), will a single line comment end potentially the context of the construct if I place it incorrectly? For example, presuming step1, step2 and step3 are functions already defined, will:

def myFunc():
    step1()
#   step2()
    step3()

(unintentionally) reduce the scope of myFunc() so that it only contains step1? If I only want to remove step2 from the 3-step sequence, must I place the # at the same level of indentation as the statements within the scope of the construct? All the code I have seen so far suggests this is a requirement, but it might just be a coding habit.

Answer 1

Syntax-wise, blank lines are ignored. Blank lines include lines that have any amount of white space followed by a comment. https://docs.python.org/2/reference/lexical_analysis.html#blank-lines Indenting a comment the way you show in your example does not change the block of code included in your function.

Convention-wise, PEP8 calls for comments indented to the same indentation as code.

Answer 2

Try it out:

def myFunc():
    print(1)
#   print(2)
    print(3)
myFunc()

which outputs:

1
3

So yeah, the answer is "Line comments don't need to match indentation". That said, PEP8 really prefers that they do, just for readability.