How to know the labels assigned by astype('category').cat.codes?

Question

I have the following dataframe called language

         lang          level 0      english         intermediate 1      spanish         intermediate 2      spanish         basic 3      english         basic 4      english         advanced 5      spanish         intermediate 6      spanish         basic 7      spanish         advanced 

I categorized each of my variables into numbers by using

language.lang.astype('category').cat.codes

and

language.level.astype('category').cat.codes

respectively. Obtaining the following data frame:

      lang   level 0      0       1 1      1       1 2      1       0 3      0       0 4      0       2 5      1       1 6      1       0 7      1       2 

Now, I would like to know if there is a way to obtain which original value corresponds to each value. I'd like to know that the 0 value in the lang column corresponds to english and so on.

Is there any function that allows me to get back this information?

Answer 1

You can generate dictionary:

c = language.lang.astype('category')  d = dict(enumerate(c.cat.categories)) print (d) {0: 'english', 1: 'spanish'} 

So then if necessary is possible map:

language['code'] = language.lang.astype('category').cat.codes  language['level_back'] = language['code'].map(d) print (language)       lang         level  code level_back 0  english  intermediate     0    english 1  spanish  intermediate     1    spanish 2  spanish         basic     1    spanish 3  english         basic     0    english 4  english      advanced     0    english 5  spanish  intermediate     1    spanish 6  spanish         basic     1    spanish 7  spanish      advanced     1    spanish