Python Map List of Strings to Integer List

Question

Let\'s say I have a list

l = [\'michael\',\'michael\',\'alice\',\'carter\']

I want to map it to the following:

k = [1,1,2,3         


        

Answer 1

How about using Pandas?

import pandas as pd
l = ['michael','michael','alice','carter']
pd.Series(l).astype('category').cat.codes.values

Answer 2

To map list of integers to list of strings I would use a dictionary, for example:

> name_number = {'michael':1, 'michael':1, 'alice':2, 'carter':3}
> print len(name_number)
  3
> print name_number['alice']
  2

Note that len(name_number) is 3, because duplicate keys are not allowed.

Answer 3

can do it pretty easy without a function :

j - list()    
for i in range (len(l)) : 
   j.append((l[i],k[i]))