Return rows in pandas dataframe where tuple in column contains a certain value

Question

I am trying to query a pandas dataframe for rows in which one column contains a tuple containing a certain value.

As an example:

   User                 Col1
0     1     (cat, dog, goat)
1     1         (cat, sheep)
2     1        (sheep, goat)
3     2          (cat, lion)
4     2  (fish, goat, lemur)
5     3           (cat, dog)
6     4          (dog, goat)
7     4                  cat

So assuming I want to return the rows where Col1 contains 'cat', is there a way to do this without iterating through each row and performing an "if" (my actual dataset has many more rows)?

df['Col1'].isin(['cat'])

and

df['Col1'].str.contains("cat")

only return 'true' for the last row

ASGM · Accepted Answer · 2022-09-28 10:53:23Z

3

You could use a lambda function within apply():

df[df["Col1"].apply(lambda x: "cat" in x)]

The lambda returns True when "cat" is in the cell. That works for both strings ("cat" in "cat" is True) and tuples ("cat" in ("cat", "dog") is True). By subsetting the df, you get all rows where the lambda is True.

edited Sep 28, 2022 at 10:53

answered Apr 6, 2015 at 16:30

ASGM

11.5k1 gold badge37 silver badges54 bronze badges

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

3 Comments

ASGM Over a year ago

Glad I could help!

Noel Evans Over a year ago

You could also just write df[df["Col1"].apply(lambda x: "cat" in x)]

ASGM Over a year ago

You're right, @NoelEvans! Changed accordingly.

Parfait · Accepted Answer · 2015-04-05 23:43:41Z

1

Why not subset your data frame and then output its results?

catdf = df[df['Col1'].str.contains("cat")]

answered Apr 5, 2015 at 23:43

Parfait

108k19 gold badges103 silver badges138 bronze badges

Comments

Mark Graph · Accepted Answer · 2015-04-06 11:57:37Z

1

Your DataFrame column contains a mixture of strings and tuples. I don't think you can avoid iterating the column. But you can iterate efficiently with the apply method. Example code follows.

import pandas as pd

# fake data - in a Series for simplicity
tlist = [('cat', 'dog', 'goat'),
    ('cat', 'sheep'),
    ('sheep', 'goat'),
    ('cat', 'lion'),
    ('fish', 'goat', 'lemur'),
    ('cat', 'dog'),
    ('dog', 'goat'),
    'cat']
s = pd.Series(tlist)

# iterate Series with a lambda function searching for 'cat'
s.apply(lambda x: 'cat' in x)

Which gave me the following output

Out[38]: 
0     True
1     True
2    False
3     True
4    False
5     True
6    False
7     True
dtype: bool

edited Apr 6, 2015 at 11:57

answered Apr 6, 2015 at 0:16

Mark Graph

5,1416 gold badges29 silver badges41 bronze badges

Collectives™ on Stack Overflow

Return rows in pandas dataframe where tuple in column contains a certain value

3 Answers 3

3 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related