pandas concatenate based on column code example

Example 1: how to concat on the basis of particular columns in pandas

In [6]: result = pd.concat(frames, keys=['x', 'y', 'z'])

Example 2: dataframe concatenate

# Pandas for Python

df['col1 & col2'] = df['col1']+df['col2']

#Output
#col1	col2	col1 & col2
#A1		A2		A1A2
#B1		B2		B1B2