merge 2 dataframes code example

Example 1: merge two dataframes based on column

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

df_outer

Example 2: join on column pandas

# df1 as main df and use the feild from df2 and map it into df1

df1.merge(df2,on='columnName',how='left')

Example 3: pandas left join

df.merge(df2, left_on = "doc_id", right_on = "doc_num", how = "left")

Example 4: combining 2 dataframes pandas

df_3 = pd.concat([df_1, df_2])

Example 5: 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 6: pandas combine two data frames with same index and same columns

pd.merge(df1, df2, left_index=True, right_index=True, how='outer')