How do I assign values based on content of columns?

Question

I would like to create a new column with a numerical value assigned based on whether pet1 contains the word 'cat' or the word 'dog'

    pet1           
0   dog             
1   dog;cat;rabbit  
2   cat;dog         
3   manbearpig      
4   hippo

I would like the end result to be as follows:

    pet1            points
0   dog             5
1   dog;cat;rabbit  5
2   cat;dog         5
3   manbearpig      0
4   hippo           0

How do I do this?

joris · Accepted Answer · 2015-06-03 22:33:13Z

2

You can use the string method contains for this.
Starting from this dataframe:

In [96]: df
Out[96]:
             pet1
0             dog
1  dog;cat;rabbit
2         cat;dog
3      manbearpig
4           hippo

You can check if each element contains the substring 'dog':

In [97]: df['pet1'].str.contains('dog')
Out[97]:
0     True
1     True
2     True
3    False
4    False
Name: pet1, dtype: bool

and then multiply by 5 to end up with your desired result:

In [98]: df['pet1'].str.contains('dog') * 5
Out[98]:
0    5
1    5
2    5
3    0
4    0
Name: pet1, dtype: int32

answered Jun 3, 2015 at 22:33

joris

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