Question

Simple question to which I can’t find any “nice” answer by myself:

Let’s say I have the following condition:

if 'foo' in mystring or 'bar' in mystring or 'hello' in mystring:
    # Do something
    pass

Where the number of or statement can be quite longer depending on the situation.

Is there a “nicer” (more Pythonic) way of writing this, without sacrificing performance ?

If thought of using any() but it takes a list of boolean-like elements, so I would have to build that list first (giving-up short circuit evaluation in the process), so I guess it’s less efficient.

Thank you very much.

Answer 1

A way could be

if any(s in mystring for s in ('foo', 'bar', 'hello')):
    pass

The thing you iterate over is a tuple, which is built upon compilation of the function, so it shouldn’t be inferior to your original version.

If you fear that the tuple will become too long, you could do

def mystringlist():
    yield 'foo'
    yield 'bar'
    yield 'hello'
if any(s in mystring for s in mystringlist()):
    pass