Pandas: Get count of column values and create a new column [duplicate]

Question

I have the following dataframe:

df
   id grp1 grp2
0   1    a  NaN
1   2    b    d

I need to create a new column with count of values from grp1 and grp2 columns.Something like below

df
   id grp1 grp2 grp_count
0   1    a  NaN      1
1   2    b    d      2

One way of achieving this is using pandas apply with a function to get the count iterating row by row which will affect the performance.

Is there a way we can do it without using pandas apply?

FBruzzesi · Accepted Answer · 2019-12-13 13:21:01Z

2

Pandas DataFrame count method ignores nan values by default, therefore:

df['grp_count'] = df[['grp1', 'grp2']].count(axis=1)

answered Dec 13, 2019 at 13:10

FBruzzesi

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