Answers for "pandas merge on columns different names"

pandas merge certain columns

df = pd.merge(df,df2[['Key_Column','Target_Column']],on='Key_Column', how='left')

merge two columns name in one header pandas

df['A'] = df[a_cols].apply(' '.join, axis=1)

pandas merge on columns different names

pd.merge(frame_1, frame_2, left_on='county_ID', right_on='countyid')