Get count unique values in a row in pandas

Question

Suppose I have the following data frame:

0     1        2
new   NaN      NaN
new   one      one
a     b        c
NaN   NaN      NaN

How would I

Answer 1

It is not as fast as coldspeed's answer with set(), but you could also do

df['_num_unique_values'] = df.T.nunique()

First the transpose of df dataframe is taken with df.T and then nunique() is used to get the count of unique values excluding NaNs.

This is added as a new column to the original dataframe.

df would now be

    0   1   2   _num_unique_values
0   new nan nan 1
1   new one one 2
2   a   b   c   3
3   nan nan nan 0