python - Reduce number of levels for large categorical variables

Question

Are there some ready to use libraries or packages for python or R to reduce the number of levels for large categorical factors?

I want to achieve something similar to R: "Binning" categorical variables but encode into the most frequently top-k factors and "other".

Answer 1

The R package forcats has fct_lump() for this purpose.

library(forcats)
fct_lump(f, n)

Where f is the factor and n is the number of most common levels to be preserved. The remaining are recoded to Other.