Check if a string contains one or more of list values in python

Question

I have a list and a string as follows.

mylist = ["tim tam", "yogurt", "strawberry"]
mystring = "I love to eat tim tam"

Now I want to check if mystring contains one or more words in mylist. If it contains the flag variable should be true, if not false.

My current code is as follows.

if mylist in mystring:
    flag = 1
else:
    flag = 0

However, I get the error TypeError: argument of type 'method' is not iterable. Not sure why it happens. Please help me.

This is inefficient, but int(any(x in mystring for x in my list)) — cs95
– cs95, Commented Dec 19, 2017 at 13:09
If you get that exception, then mystring is not what you think it is, but a method. — tobias_k
– tobias_k, Commented Dec 19, 2017 at 13:10

Cory Kramer · Accepted Answer · 2017-12-19 13:09:10Z

4

You can use a generator expression in any to check each substring against your original string

>>> flag = any(i in mystring for i in mylist)
>>> flag
True

If you want an int instead of a bool you can modify the above to

>>> flag = int(any(i in mystring for i in mylist))
>>> flag
1

answered Dec 19, 2017 at 13:09

Cory Kramer

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1 Comment

You can add that all and any are short circuiting in Python and this behavior is guaranteed.

TigerClaw · Accepted Answer · 2017-12-19 13:16:46Z

1

You can use str.contains- or lambda-function for filtering (I use it for DataFrame).

df=df.str.contains("keyword1|keyword2|keyword3", na=False)]

or

ddf[df.apply(lambda r: r.str.contains('keyword1|keyword2|keyword3', case=False).any(), axis=1)]

Example:

mylist = 'tim tam|yogurt|strawberry'   
df = pd.DataFrame(df[df[[0,1,2,3...]].apply(lambda r: r.str.contains(mylist, case=False).any(), axis=1)])

answered Dec 19, 2017 at 13:16

TigerClaw

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Huh... where has pandas come from?