Test a string for a substring

Question

Is there an easy way to test a Python string "xxxxABCDyyyy" to see if "ABCD" is contained within it?

score 224 · Accepted Answer · answered Mar 29 '11 at 13:10

224

if "ABCD" in "xxxxABCDyyyy":
    # whatever

answered Mar 29 '11 at 13:10

Sven Marnach

5

This works here, but may not give the expected results if you are testing against a non-string. E.g. if testing against a list of strings (perhaps with `if "ABCD" in ["xxxxabcdyyyy"]`), this can fail silently. – GreenMatt Mar 29 '11 at 15:37
2

@GreenMatt if you know it's a list just say `if 'ABCD' in list[0]`. – Jossie Calderon Jul 20 '16 at 13:08

score 36 · Answer 2 · edited Mar 23 '19 at 09:27

36

There are several other ways, besides using the in operator (easiest):

index()

>>> try:
...   "xxxxABCDyyyy".index("test")
... except ValueError:
...   print "not found"
... else:
...   print "found"
...
not found

find()

>>> if "xxxxABCDyyyy".find("ABCD") != -1:
...   print "found"
...
found

re

>>> import re
>>> if re.search("ABCD" , "xxxxABCDyyyy"):
...  print "found"
...
found

edited Mar 23 '19 at 09:27

Sociopath

answered Mar 29 '11 at 13:19

kurumi

5

The last one requires and `re.escape` call in the general case though. – Mar 29 '11 at 13:28

2 Answers2