Find array item in a string

Question

I know can use string.find() to find a substring in a string.

But what is the easiest way to find out if one of the array items has a substring match in a string without using a loop?

Pseudocode:

string = 'I would like an apple.'
search = ['apple','orange', 'banana']
string.find(search) # == True

Answer 1

You could use a generator expression (which somehow is a loop)

any(x in string for x in search)

The generator expression is the part inside the parentheses. It creates an iterable that returns the value of x in string for each x in the tuple search. x in string in turn returns whether string contains the substring x. Finally, the Python built-in any() iterates over the iterable it gets passed and returns if any of its items evaluate to True.

Alternatively, you could use a regular expression to avoid the loop:

import re
re.search("|".join(search), string)

I would go for the first solution, since regular expressions have pitfalls (escaping etc.).

Answer 2

Strings in Python are sequences, and you can do a quick membership test by just asking if one string exists inside of another:

>>> mystr = "I'd like an apple"
>>> 'apple' in mystr
True

Sven got it right in his first answer above. To check if any of several strings exist in some other string, you'd do:

>>> ls = ['apple', 'orange']
>>> any(x in mystr for x in ls)
True

Worth noting for future reference is that the built-in 'all()' function would return true only if all items in 'ls' were members of 'mystr':

>>> ls = ['apple', 'orange']
>>> all(x in mystr for x in ls)
False
>>> ls = ['apple', 'like']
>>> all(x in mystr for x in ls)
True