Coding fix

[MariaGorodetski]

conversion of single categories into Int16 when 'coding' is asked

[alondmnt]

looks fine and simple, left one question

[alondmnt]

I may have found a solution for sorted categories (assuming that I can still remember what we tried to achieve).
For example, for months:

pd.Categorical(['August', 'May', 'April', 'January'])\
    .set_categories(codings_df.loc['042_03'].sort_values('coding')['english'], ordered=True)\
    .sort_values()

generates a properly sorted series and ordered categorical type:

['January', 'April', 'May', 'August']
Categories (13, object): ['Was not absent at all' < 'January' < 'February' < 'March' ... 'September' < 'October' < 'November' < 'December']

I'll work on adding it and keep you updated.