Convert Two column data frame to occurrence matrix in pandas

Question

Hi all I have a csv file which contains data as the format below

A   a
A   b
B   f
B   g
B   e
B   h
C   d
C   e
C   f

The first column contains items second column contains available feature from feature vector=[a,b,c,d,e,f,g,h] I want to convert this to occurence matrix look like below

    a,b,c,d,e,f,g,h
A   1,1,0,0,0,0,0,0
B   0,0,0,0,1,1,1,1
C   0,0,0,1,1,1,0,0

Can anyone tell me how to do this using pandas?

Answer 1

Here is another way to do it using pd.get_dummies().

import pandas as pd

# your data
# =======================
df

  col1 col2
0    A    a
1    A    b
2    B    f
3    B    g
4    B    e
5    B    h
6    C    d
7    C    e
8    C    f

# processing
# ===================================
pd.get_dummies(df.col2).groupby(df.col1).apply(max)

      a  b  d  e  f  g  h
col1                     
A     1  1  0  0  0  0  0
B     0  0  0  1  1  1  1
C     0  0  1  1  1  0  0