Replace whole string if it contains substring in pandas

Question

I want to replace all strings that contain a specific substring. So for example if I have this dataframe:

import pandas as pd
df = pd.DataFrame({'name': ['Bob', 'Jane', 'Alice'], 
                   'sport': ['tennis', 'football', 'basketball']})

I could replace football with the string 'ball sport' like this:

df.replace({'sport': {'football': 'ball sport'}})

What I want though is to replace everything that contains ball (in this case football and basketball) with 'ball sport'. Something like this:

df.replace({'sport': {'[strings that contain ball]': 'ball sport'}})

Answer 1

You can use apply with a lambda. The x parameter of the lambda function will be each value in the 'sport' column:

df.sport = df.sport.apply(lambda x: 'ball sport' if 'ball' in x else x)

Answer 2

you can use str.replace

df.sport.str.replace(r'(^.*ball.*$)', 'ball sport')

0        tennis
1    ball sport
2    ball sport
Name: sport, dtype: object

reassign with

df['sport'] = df.sport.str.replace(r'(^.*ball.*$)', 'ball sport')
df

Answer 3

A different str.contains

 df['support'][df.name.str.contains('ball')] = 'ball support'

Answer 4

You can use a lambda function also:

data  = {"number": [1, 2, 3, 4, 5], "function": ['IT', 'IT application', 
'IT digital', 'other', 'Digital'] }
df = pd.DataFrame(data)  
df.function = df.function.apply(lambda x: 'IT' if 'IT' in x else x)