pandas.Index.duplicated

Index.duplicated(keep='first')

Return boolean np.ndarray denoting duplicate values

Parameters:

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

• 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.

Returns:

duplicated : np.ndarray