DataFrame.duplicated(self, subset: Union[Hashable, Sequence[Hashable], NoneType] = None, keep: Union[str, bool] = 'first') → 'Series'[source]

Return boolean Series denoting duplicate rows.

Considering certain columns is optional.

subsetcolumn label or sequence of labels, optional

Only consider certain columns for identifying duplicates, by default use all of the columns.

keep{‘first’, ‘last’, False}, default ‘first’

Determines which duplicates (if any) to mark.

  • first : Mark duplicates as True except for the first occurrence.

  • last : Mark duplicates as True except for the last occurrence.

  • False : Mark all duplicates as True.