Populating Pandas DataFrame column based on dictionary of regex

Question

I have a dataframe like the following:

    GE    GO
1   AD    Weiss
2   KI    Ruby
3   OH    Port
4   ER    Rose
5   KI    Rose
6   JJ    Weiss
7   OH    7UP         


        

Answer 1

One option is to make use of re module with a map on the GO column:

import re
df['OUT'] = df.GO.map(lambda x: next(Dic[k] for k in Dic if re.search(k, x)))
df

This raises error if none of the pattern matches the string. If there are cases where string doesn't match any pattern, you can write a custom function to capture the exception and return None:

import re
def findCat(x):
    try:
        return next(Dic[k] for k in Dic if re.search(k, x))
    except:
        return None

df['OUT'] = df.GO.map(findCat)
df