how to join dataframes in python code example
Example 1: join on column pandas
df1.merge(df2,on='columnName',how='left')
Example 2: pandas left join
df.merge(df2, left_on = "doc_id", right_on = "doc_num", how = "left")
Example 3: pandas merge multiple dataframes
import pandas as pd
from functools import reduce
data_frames = [df1, df2, df3]
df_merged = reduce(lambda left,right: pd.merge(left,right,on=['key_col'],
how='outer'), data_frames)
Example 4: merge two dataframes based on column
df_merge_col = pd.merge(df_row, df3, on='id')
df_merge_col
Example 5: python dataframe left join
>>> left.merge(right, on='user_id', how='left')
Example 6: join to dataframes pandas
>>> df.join(other.set_index('key'), on='key')
key A B
0 K0 A0 B0
1 K1 A1 B1
2 K2 A2 B2
3 K3 A3 NaN
4 K4 A4 NaN
5 K5 A5 NaN