Data Wrangling in Python – How to List Unique Values In A pandas Column

List Unique Values In A pandas Column

Special thanks to Bob Haffner for pointing out a better way of doing it.


/* Import modules */
import pandas as pd

/* Set ipython's max row display */
pd.set_option('display.max_row', 1000)

/* Set iPython's max column width to 50 */
pd.set_option('display.max_columns', 50)

Create an example dataframe

/* Create an example dataframe */
data = {'name': ['Jason', 'Molly', 'Tina', 'Jake', 'Amy'], 
        'year': [2012, 2012, 2013, 2014, 2014], 
        'reports': [4, 24, 31, 2, 3]}

df = pd.DataFrame(data, index = ['Cochice', 'Pima', 'Santa Cruz', 'Maricopa', 'Yuma'])
name year reports
Cochice Jason 2012 4
Pima Molly 2012 24
Santa Cruz Tina 2013 31
Maricopa Jake 2014 2
Yuma Amy 2014 3

List unique values

/* List unique values in the df['name'] column */
array(['Jason', 'Molly', 'Tina', 'Jake', 'Amy'], dtype=object)

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