查找Python中的另一个列表中是否存在任何列表元素

Question

The question is about a quicker, ie. more pythonic, way to test if any of the elements in an iterable exists inside another iterable.

What I am trying to do is something like:

if "foo" in terms or "bar" in terms or "baz" in terms: pass

But apparently this way repeats the 'in terms' clause and bloats the code, especially when we are dealing with many more elements. So I wondered whether is a better way to do this in python.

Answer 1

You could also consider in your special case if it is possible to use set s instead of iterables. If both ( foobarbaz and terms ) are set s, then you can just write

if foobarbaz & terms:
    pass

This isn't particularly faster than your way, but it is smaller code by far and thus probably better for reading.

And of course, not all iterables can be converted to set s, so it depends on your usecase.

Answer 2

Figured out a way, posting here for easy reference. Try this:

if any(term in terms for term in ("foo", "bar", "baz")): pass

Answer 3

Faster than Alfe's answer, since it only tests for, rather than calculates the, intersection

if not set(terms).isdisjoint({'foo', 'bar', 'baz'}):
    pass