Searching a pandas dataframe for multiple strings

Question

I have a dataframe (df) with a column 'Names' and I have a separate list of strings which are of the form:

info = ['AAA.123+456.789', 'BBB.987+654.321', 'CCC.321-654.987']

and so on. I want to search the 'Names' column in df using strings in the list and store the result in a separate dataframe (df2). I used:

df2 = df.loc[df['Names'].str.contains('|'.join(info))]

however the output for df2 (in the spyder variable explorer) was either an empty dataframe or only one of the results was returned. I'm not sure how I can fix this so any advice would be appreciated - thanks!

Edit

Index	Names	Quantity 1	Quantity 2	Quantity 3	Quantity 4
0	AAA	12.3	4.56	7.89	10.1112
1	BBB	3.21	65.4	98.7	1.21110
2	CCC	456.23	1.23	10101	101.112
3	DDD	6.4	3.21	0.2029	1211.10

is a sample of df's contents (it's 6 columns and a very high number of rows)

Edit 2

Have relabelled 'list' as 'info' on the suggestion of Serge in comments

Do not call your list by list. That is reserved to define lists. — Serge de Gosson de Varennes
– Serge de Gosson de Varennes, Commented Nov 24, 2021 at 16:56
additionally, try to provide a minmal reproducible example. Try to create some dummy data that produces the same problem. For example, use less complex string patterns to start with — mnist
– mnist, Commented Nov 24, 2021 at 16:58

Serge de Gosson de Varennes · Accepted Answer · 2021-11-24 17:41:44Z

2

You can do this. If your df is

df = pd.DataFrame({"Names":['AAA.123+456.789', "BBB.987+654.321", "W1234", "A_aa_1+.", "Z54"], "col1":[1,2,3,4,5]})

info = ['AAA.123+456.789', 'BBB.987+654.321', 'CCC.321-654.987']

and

df2 = df[df['Name'].isin(info)]

gives:

    Names  col1
0  AAA.123+456.789     1
1  BBB.987+654.321     2

edited Nov 24, 2021 at 17:41

answered Nov 24, 2021 at 17:14

Serge de Gosson de Varennes

11.6k4 gold badges30 silver badges60 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Akshay Over a year ago

Hmmn ok, the weird thing is when I use the above method, I still get an Empty DataFrame with 6 columns as the result for df2? I'm almost certain the strings in 'info' are in the df as I have copied over the corresponding entries in df into info...

Akshay Over a year ago

Okay amazing think it works now, thanks so much!

Collectives™ on Stack Overflow

Searching a pandas dataframe for multiple strings

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related