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Pandas DataFrame nunique() Method

❮ DataFrame Reference


Example

Return the number of unique values for each column:

import pandas as pd

data = [[10, 20, 0], [10, 10, 10], [10, 20, 30]]

df = pd.DataFrame(data)

print(df.nunique())
Try it Yourself »

Definition and Usage

The nunique() method returns the number of unique values for each column.

By specifying the column axis (axis='columns'), the nunique() method searches column-wise and returns the number of unique values for each row.


Syntax

dataframe.nunique(axis, dropna)

Parameters

The parameters are keyword arguments.

Parameter Value Description
axis 0
1
'index'
'columns'
Optional, Which axis to check, default 0.
dropna True
False
Optional, default True. Set to False if the result should NOT drop NULL values

Return Value

A Series with the number of unique values for each column or row.

This function does NOT make changes to the original DataFrame object.


❮ DataFrame Reference

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