API · Pandas
Pandas Series Series.nunique() Function
The Pandas Series.nunique method counts the unique values in the Python Pandas Series.
Python Pandas Series.nunique() method counts the unique values in the Python Pandas Series.
Syntax of pandas.Series.nunique():
Series.nunique(dropna=True)
Parameters
dropna |
True by default.If True, NaN is excluded. If False, NaN is also counted. |
Return
It returns an integer that counts the unique values in the caller Pandas Series.
Example Codes: Series.nunique() Method
import pandas as pd
import numpy as np
ser = pd.Series([1, 2, 3, np.nan, 3, 4, np.nan],
name = 'No.')
print(ser.nunique())
Output:
4
The caller Series has 4 unique values - [1, 2, 3, 4] except NaN; therefore, Series.nunique() method returns 4 because NaN is excluded by default.
Example Codes: Series.nunique() Method With dropna=False
import pandas as pd
import numpy as np
ser = pd.Series([1, 2, 3, np.nan, 3, 4, np.nan],
name = 'No.')
print(ser.nunique(dropna=False))
Output:
5
When dropna is False, NaN is also counted in Series.nunique() method.
