How to make a pandas crosstab with percentages?

Question

Given a dataframe with different categorical variables, how do I return a cross-tabulation with percentages instead of frequencies?

df = pd.DataFrame({\'A\' : [\         


        

Answer 1

pd.crosstab(df.A, df.B).apply(lambda r: r/r.sum(), axis=1)

Basically you just have the function that does row/row.sum(), and you use apply with axis=1 to apply it by row.

(If doing this in Python 2, you should use from __future__ import division to make sure division always returns a float.)