duplicated(self, keep='first') -> 'Series'

Duplicated values are indicated as True values in the resulting Series. Either all duplicates, all except the first or all except the last occurrence of duplicates can be indicated.

Parameters

keep : {'first', 'last', False}, default 'first'

Method to handle dropping duplicates:

Returns

Series[bool]

Series indicating whether each value has occurred in the preceding values.

Indicate duplicate Series values.

See Also

DataFrame.duplicated

Equivalent method on pandas.DataFrame.

Index.duplicated

Equivalent method on pandas.Index.

Series.drop_duplicates

Remove duplicate values from Series.

Examples

By default, for each set of duplicated values, the first occurrence is set on False and all others on True:

This example is valid syntax, but we were not able to check execution

>>> animals = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama'])
... animals.duplicated()
0    False
1    False
2     True
3    False
4     True
dtype: bool

which is equivalent to

This example is valid syntax, but we were not able to check execution

>>> animals.duplicated(keep='first')
0    False
1    False
2     True
3    False
4     True
dtype: bool

By using 'last', the last occurrence of each set of duplicated values is set on False and all others on True:

This example is valid syntax, but we were not able to check execution

>>> animals.duplicated(keep='last')
0     True
1    False
2     True
3    False
4    False
dtype: bool

By setting keep on False , all duplicates are True:

This example is valid syntax, but we were not able to check execution

>>> animals.duplicated(keep=False)
0     True
1    False
2     True
3    False
4     True
dtype: bool

See :

Back References

The following pages refer to to this document either explicitly or contain code examples using this.

pandas.core.indexes.base.Index.duplicated pandas.core.series.Series.drop_duplicates pandas.core.indexes.multi.MultiIndex.duplicated pandas.core.frame.DataFrame.duplicated

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File: /pandas/core/series.py#2190
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