.. xfunction:: datatable.codes
:src: src/core/expr/fexpr_codes.cc pyfn_codes
:tests: tests/types/test-categorical.py
:cvar: doc_dt_codes
:signature: codes(cols)
.. x-version-added:: 1.1.0
Get integer codes for categorical data.
Parameters
----------
cols: FExpr
Input categorical data.
return: FExpr
f-expression that returns integer codes for each column
from `cols`.
except: TypeError
The exception is raised when one of the columns from `cols`
has a non-categorical type.