How to get Unique Values of a Column in Pandas DataFrame?
Pandas DataFrame - Get Unique Values in a Column
To get unique values in a column in DataFrame,
- Access the column using indexing mechanism
DataFrame['columName']
. This expression returns the column as Series object. - Call pandas.unique() and pass the Series object obtained in the above step, as argument.
Syntax
The syntax to get unique values of column col
in a DataFrame df
is
pandas.unique(df['col'])
Examples
1. Get unique values in a specified column
In this example, we take a DataFrame with two columns: name
, age
; and get the unique values of the column age
.
Python Program
import pandas as pd
df = pd.DataFrame({'name':['a', 'b', 'c', 'd', 'e'],
'age' :[20, 21, 20, 19, 21]})
result = pd.unique(df['age'])
print(result)
Output
[20 21 19]
Summary
In this Pandas Tutorial, we learned how to get the unique values of a column in DataFrame.