Suppose I have two DataFrames like so:
left = pd.DataFrame({\'key1\': [\'foo\', \'bar\'], \'lval\': [1, 2]})
right = pd.DataFrame({\'key2\': [\'foo\', \'bar
df_1.join(df_2)
df_1.merge(df_2)
on
parameter has different meaning in both casesdf_1.merge(df_2, on='column_1')
df_1.join(df_2, on='column_1') // It will throw error
df_1.join(df_2.set_index('column_1'), on='column_1')