Pandas: get index of each element

Question

I guess this is a duplicate of Find element's index in pandas Series .

This is my dataframe;

      WORD1    CAT1   
    elephant   animal  
        lion   animal
       tiger   animal
      hoopoe    bird 
    hornbill    bird
   sunflower   flower
        rose   flower
     giraffe   animal
       zebra   animal
     sparrow    bird  
        duck   animal  

I would like to get the index of each element from 'CAT1';

Let me put it this way;

for d in data['CAT1']:
    print data[data['CAT1'] == d].index[0]
...
0
0
0
3
3
5
5
0
0
3
0

The above returns the index, but falters when there are duplicates. How do I get this rectified?

Answer 1

You can enumerate in Python to get the indices along with the items:

for i, d in enumerate(data['CAT1']):
     print(i)

If you want to select from WORD1 by CAT1, you could zip them, for example:

birds = [w for w, c in zip(data['WORD1'], data['CAT1']) if c == "bird")]

Note: str.index is a method for finding the index of a sub-string within a string.