Does Python have a string 'contains' substring method?

I'm looking for a string.contains or string.indexof method in Python.

I want to do:

if not somestring.contains("blah"):
   continue

您可以使用in运算符:

if "blah" not in somestring: 
    continue

If it's just a substring search you can use string.find("substring") .

You do have to be a little careful with find , index , and in though, as they are substring searches. In other words, this:

s = "This be a string"
if s.find("is") == -1:
    print "No 'is' here!"
else:
    print "Found 'is' in the string."

It would print Found 'is' in the string. Similarly, if "is" in s: would evaluate to True . This may or may not be what you want.


if needle in haystack: is the normal use, as @Michael says -- it relies on the in operator, more readable and faster than a method call.

If you truly need a method instead of an operator (eg to do some weird key= for a very peculiar sort...?), that would be 'haystack'.__contains__ . But since your example is for use in an if , I guess you don't really mean what you say;-). It's not good form (nor readable, nor efficient) to use special methods directly -- they're meant to be used, instead, through the operators and builtins that delegate to them.

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