Title: Pandas: Long To Wide Format
Slug: pandas_long_to_wide
Summary: Pandas: Long To Wide Format
Date: 2016-05-01 12:00
Category: Python
Tags: Data Wrangling
Authors: Chris Albon

import modules



In [2]:

    
import pandas as pd

Create "long" dataframe



In [3]:

    
raw_data = {'patient': [1, 1, 1, 2, 2], 
        'obs': [1, 2, 3, 1, 2], 
        'treatment': [0, 1, 0, 1, 0],
        'score': [6252, 24243, 2345, 2342, 23525]} 
df = pd.DataFrame(raw_data, columns = ['patient', 'obs', 'treatment', 'score'])
df

Make a "wide" data

Now we will create a "wide" dataframe with the rows by patient number, the columns being by observation number, and the cell values being the score values.



In [4]:

    
df.pivot(index='patient', columns='obs', values='score')

obs	1	2	3
patient
1	6252.0	24243.0	2345.0
2	2342.0	23525.0	NaN