Select row using the length of list in pandas cell

Question

I have a table df

    a   b    c
1   x   y   [x]

2   x   z   [c,d]

3   x   t   [e,f,g]

Just wondering how to select the row using the length of c column

such as

df.loc[len(df.c) >1]

I know this is not right.... what should be the right one?

score 34 · Answer 1 · answered Dec 08 '17 at 19:40

34

Try this:

df[df.c.map(len)>1]

answered Dec 08 '17 at 19:40

Tianbo Ji

351
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4

4

`df[df['class'].map(len) >1 ] ` – Sadra Mar 03 '21 at 04:07

score 3 · Accepted Answer · answered Dec 08 '17 at 18:46

3

You can using

df.loc[np.array(list(map(len,df.c.values)))>1]

answered Dec 08 '17 at 18:46

BENY

317,841
20
164
234

score 1 · Answer 3 · answered Apr 03 '20 at 12:16

1

With apply:

df[df.c.apply(lambda x: len(x) > 1)]

answered Apr 03 '20 at 12:16

Mac C.

153
10

score 0 · Answer 4 · answered Aug 10 '20 at 22:09

You can also create a fourth column which would contain the length of each list in column "c". Then filter out rows such that entries in the new column is greater than 1.

df["length"] = df["c"].apply(lambda x: len(x) > 1)
df = df.loc[df["length"], :].drop(["length"], axis=1)

Select row using the length of list in pandas cell

4 Answers4

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