dataframe merge on multiple columns code example

Example 1: merge two dataframes based on column

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

df_outer

Example 2: pd merge on multiple columns

new_df = pd.merge(A_df, B_df,  how='left', left_on=['A_c1','c2'], right_on = ['B_c1','c2'])

Example 3: pandas merge multiple dataframes

import pandas as pd
from functools import reduce

# compile the list of dataframes you want to merge
data_frames = [df1, df2, df3]
df_merged = reduce(lambda  left,right: pd.merge(left,right,on=['key_col'],
                                            how='outer'), data_frames)

Example 4: combine dataframes with two matching columns

merged_df = DF2.merge(DF1, how = 'inner', on = ['date', 'hours'])

Example 5: pandas merge two columns from different dataframes

#suppose you have two dataframes df1 and df2, and 
#you need to merge them along the column id
df_merge_col = pd.merge(df1, df2, on='id')

Example 6: merge two columns pandas

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