how to merge data frames code example

Example 1: dataframe concatenate

# Pandas for Python

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

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

Example 2: combine df columns python

df["period"] = df["Year"] + df["quarter"]