Question

I’m working through a Python 3 book and came across the string function isidentifier(). The text description is “s.isidentifier() : Returns True if s is non empty and is a valid identifier”. I tested it in the Python Shell like this:

>>> s = 'test'
>>> s.isidentifier()
True
>>> 'blah'.isidentifier()
True

I would expect the 2nd statement to return false since ‘blah’ is not held in a variable. Can anyone explain this? Thanks.

Answer 1

Returns True if s is non empty and is a valid identifier.

What they mean is that s could be valid as an identifier. It doesn’t imply that it is an identifier that’s in use.

Your first example is showing the same thing: ‘test’ (what isidentifier is actually checking) is not the name of a variable either. I think you meant

>>> 's'.isidentifier()
True