Map ranges of codes to strings in python

Question

I have the following df I want to map. Postal code is an int type and I want create a region column with codes that fall under certain ranges to be mapped to specific regions for example

range(2000-2999):"NSW", range(3000-3999):"Victoria", range(4000-5000): "Something", 9013: "Kangaroo"

Postal Code   Region
2000
2001
3001
4001
4999
9013

I did the below however, i got an error - "TypeError: argument of type 'int' is not iterable"

df['Region']=df['Postal Code'].apply(lambda x:next((v for k, v in postal.items() if x in k),0))

if you could please provide a better way to iterate through a column with all integers and map specific ranges of postal codes to certain regions that would be highly appreciated!

Thanks

Answer 1

I'd use pd.IntervalIndex with map :

s = pd.Series(['NSW', 'Victoria', 'Something', 'Kangaroo'], 
              index=pd.IntervalIndex.from_arrays([9013,2000,3000,4000],
                                                 [9013,2999,3999,5000], 
                                                 closed='both'))

df['Region'] = df['Postal Code'].map(s)
print(df)

Output:

   Postal Code     Region
0         2000   Victoria
1         2001   Victoria
2         3001  Something
3         4001   Kangaroo
4         4999   Kangaroo
5         9013        NSW

Answer 2

The error occurred because you put the ,0 in the wrong parentheses.

df['Region']=df['Postal Code'].apply(lambda x:next((v for k, v in postal.items() if x in k)),0)