merge two columns in dataframe python code example

Example 1: merge two dataframes based on column

df_outer = pd.merge(df1, df2, on='id', how='outer')

df_outer

Example 2: how to merge two dataframes

df_merge_col = pd.merge(df_row, df3, on='id')

df_merge_col

Example 3: merge two columns pandas

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

Example 4: pandas dataframe add two columns int and string

df = df['Day'].map(str) + '-' + df['Month'].map(str) + '-' + df['Year'].map(str)