Create new indicator columns based on values in another column

December 17, 2021

I have some data that looks like this:

import pandas as pd

fruits = ['apple', 'pear', 'peach']

df = pd.DataFrame({'col1':['i want an apple', 'i hate pears', 'please buy a peach and an apple', 'I want squash']})

print(df.head())

                              col1
0                  i want an apple
1                     i hate pears
2  please buy a peach and an apple
3                    I want squash

I need a solution that creates a column for each item in fruits and gives a 1 or 0 value indicating whether or not col contains that value. Ideally, the output will look like this:

goal_df = pd.DataFrame({'col1':['i want an apple', 'i hate pears', 'please buy a peach and an apple', 'I want squash'],
                        'apple': [1, 0, 1, 0],
                        'pear': [0, 1, 0, 0],
                        'peach': [0, 0, 1, 0]})

print(goal_df.head())


                              col1  apple  pear  peach
0                  i want an apple      1     0      0
1                     i hate pears      0     1      0
2  please buy a peach and an apple      1     0      1
3                    I want squash      0     0      0

I tried this but it did not work:

for i in fruits:
    if df['col1'].str.contains(i):
        df[i] = 1
    else:
        df[i] = 0

>Solution :

items = ['apple', 'pear', 'peach']
for it in items:
    df[it] = df['col1'].str.contains(it, case=False).astype(int)

Output:

>>> df
                              col1  apple  pear  peach
0                  i want an apple      1     0      0
1                     i hate pears      0     1      0
2  please buy a peach and an apple      1     0      1
3                    I want squash      0     0      0