Get count of values across columns-Pandas DataFrame

Question

I have a Pandas DataFrame like following:

               A              B              C
0   192.168.2.85   192.168.2.85  124.43.113.22
1  192.248.8.183  192         


        

Answer 1

df['Counts'] = df[['col1','col2','col3']].groupby(['col1','col2','col3']).transform('count')

Answer 2

stack it first and then use value_counts:

In [14]: df.stack().value_counts()
Out[14]: 
192.248.8.183    3   
192.168.2.85     3   
66.249.74.52     2   
192.168.2.161    2   
124.43.113.22    1   
dtype: int64