python pandas merge two dataframes code example

Example 1: combining 2 dataframes pandas

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

Example 2: 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 3: how to merge two pandas dataframes on a column

import pandas as pd
T1 = pd.merge(T1, T2, on=T1.index, how='outer')

Example 4: python dataframe left join

>>> left.merge(right, on='user_id', how='left')

Example 5: dataframe concatenate

# Pandas for Python

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

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

Example 6: how to merge two column pandas

DataFrame["new_column"] = DataFrame["column1"] + DataFrame["column2"]