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Get unique values from a column in Pandas DataFrame
  • Last Updated : 10 Dec, 2018

Let’s discuss how to get unique values from a column in Pandas DataFrame.

Create a simple dataframe with dictionary of lists, say columns name are A, B, C, D, E with duplicate elements.

Now, let’s get the unique values of a column in this dataframe.

Example #1: Get the unique values of ‘B’ column




# Import pandas package 
import pandas as pd
  
# create a dictionary with five fields each
data = {
    'A':['A1', 'A2', 'A3', 'A4', 'A5'], 
    'B':['B1', 'B2', 'B3', 'B4', 'B4'], 
    'C':['C1', 'C2', 'C3', 'C3', 'C3'], 
    'D':['D1', 'D2', 'D2', 'D2', 'D2'], 
    'E':['E1', 'E1', 'E1', 'E1', 'E1'] }
  
# Convert the dictionary into DataFrame 
df = pd.DataFrame(data)
  
# Get the unique values of 'B' column
df.B.unique()

Output:



 
Example #2: Get the unique values of ‘E’ column




# Import pandas package 
import pandas as pd
  
# create a dictionary with five fields each
data = {
    'A':['A1', 'A2', 'A3', 'A4', 'A5'], 
    'B':['B1', 'B2', 'B3', 'B4', 'B4'], 
    'C':['C1', 'C2', 'C3', 'C3', 'C3'], 
    'D':['D1', 'D2', 'D2', 'D2', 'D2'], 
    'E':['E1', 'E1', 'E1', 'E1', 'E1'] }
  
# Convert the dictionary into DataFrame 
df = pd.DataFrame(data)
  
# Get the unique values of 'E' column
df.E.unique()

Output:

Example #3: Get number of unique values in a column




# Import pandas package 
import pandas as pd
  
# create a dictionary with five fields each
data = {
    'A':['A1', 'A2', 'A3', 'A4', 'A5'], 
    'B':['B1', 'B2', 'B3', 'B4', 'B4'], 
    'C':['C1', 'C2', 'C3', 'C3', 'C3'], 
    'D':['D1', 'D2', 'D2', 'D2', 'D2'], 
    'E':['E1', 'E1', 'E1', 'E1', 'E1'] }
  
# Convert the dictionary into DataFrame 
df = pd.DataFrame(data)
  
# Get number of unique values in column 'C'
df.C.nunique(dropna = True)

Output:

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