how to replace an entire column on Pandas.DataFrame
If you don't mind getting a new data frame object returned as opposed to updating the original Pandas .assign() will avoid SettingWithCopyWarning
. Your example:
df = df.assign(B=df1['E'])
If the indices match then:
df['B'] = df1['E']
should work otherwise:
df['B'] = df1['E'].values
will work so long as the length of the elements matches
Simply do:
df.B = df1.E
That's all!
For those that struggle with the "SettingWithCopy" warning, here's a workaround which may not be so efficient, but still gets the job done.
Suppose you with to overwrite column_1 and column_3, but retain column_2 and column_4
columns_to_overwrite = ["column_1", "column_3"]
First delete the columns that you intend to replace...
original_df.drop(labels=columns_to_overwrite, axis="columns", inplace=True)
... then re-insert the columns, but using the values that you intended to overwrite
original_df[columns_to_overwrite] = other_data_frame[columns_to_overwrite]