exception pandas.errors.SettingWithCopyError[source]#

Exception raised when trying to set on a copied slice from a DataFrame.

The mode.chained_assignment needs to be set to set to ‘raise.’ This can happen unintentionally when chained indexing.

For more information on evaluation order, see the user guide.

For more information on view vs. copy, see the user guide.


>>> pd.options.mode.chained_assignment = 'raise'
>>> df = pd.DataFrame({'A': [1, 1, 1, 2, 2]}, columns=['A'])
>>> df.loc[0:3]['A'] = 'a' 
... # SettingWithCopyError: A value is trying to be set on a copy of a...