Answers for "how to add two merge two dataframes in pandas"

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)

how to merge two column pandas

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