Working with list inside a Pandas dataframe

Question

I have the following dataframe -

ID | Column1 |
0  |  []     | 
1  |  [1,2]  | 
2  |  []     |

I want a column which gives the length of the list in column1. Result should look like -

ID | Column1 | Column2 |
0  |  []     |   0     |
1  |  [1,2]  |   2     |
2  |  []     |   0     |

I tried using lambda function but it is not giving the number of rows in the data frame as every entry in column 2 -

df1 = df.assign(Column2 = lambda x: (len(x['Column1'])))

Can someone please help me out here?

Works perfect! Thanks. Can you please point out why what I am trying to use is wrong? — tester559, May 23 '21 at 17:17
Got it. Thanks for the help. You can write your comment as an answer and I will accept it. — tester559, May 23 '21 at 17:22

score 0 · Accepted Answer · answered May 23 '21 at 17:19

0

I'd iterate through each element in Column1, get its length, save it in a list and then assign it to a new Column2. This would be summarized with:

df['Column2'] = [len(x) for x in df['Column1']]

answered May 23 '21 at 17:19

akis

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Working with list inside a Pandas dataframe

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