How do I check if a given Python string is a substring of another one? [duplicate]

Question

I have two strings and I would like to check whether the first is a substring of the other. Does Python have such a built-in functionality?

It is already answered here:stackoverflow.com/questions/2590503/… — Saurabh Gokhale
– Saurabh Gokhale, Commented Feb 28, 2011 at 15:15

Andrew Hare · Accepted Answer · 2011-02-28 15:14:24Z

516

Try using in like this:

>>> x = 'hello'
>>> y = 'll'
>>> y in x
True

answered Feb 28, 2011 at 15:14

Andrew Hare

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1 Comment

What about complexity as compare to using regex?

Martin Stone · Accepted Answer · 2011-02-28 15:14:19Z

56

Try

isSubstring = first in theOther

answered Feb 28, 2011 at 15:14

Martin Stone

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cs95 · Accepted Answer · 2017-11-08 18:06:46Z

43

string.find("substring") will help you. This function returns -1 when there is no substring.

cs95

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answered Feb 28, 2011 at 15:16

Daniel Wehner

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What if I was looking for the position of the third or fourth occurrence of 'e', or the likes thereof?

python supports regulary expressions (regex). What ever you are looking for make a regex-group auto of it, afterwards you can select the 3rd group.