pandas.DataFrame.nunique#

DataFrame.nunique(axis=0, dropna=True)[source]#

Count number of distinct elements in specified axis.

Return Series with number of distinct elements. Can ignore NaN values.

Parameters:

axis{0 or ‘index’, 1 or ‘columns’}, default 0: The axis to use. 0 or ‘index’ for row-wise, 1 or ‘columns’ for column-wise.
dropnabool, default True: Don’t include NaN in the counts.

Returns:

Series: Series with counts of unique values per row or column, depending on axis.

See also

Examples

>>> df = pd.DataFrame({"A": [4, 5, 6], "B": [4, 1, 1]})
>>> df.nunique()
A    3
B    2
dtype: int64

>>> df.nunique(axis=1)
0    1
1    2
2    2
dtype: int64