Polars - with_columns on columns that end in a "D" and are of type datetime

Question

I can do the first part with

df.with_columns(pl.col("^.+D$"))

and the second part with

df.with_columns(pl.col(pl.datatypes.Datetime))

How do I join the two conditions with an "and"?

Answer 1

You could use selectors:

import polars.selectors as cs

df.with_columns(cs.datetime() & cs.ends_with('D'))

# or
df.with_columns(cs.datetime() & cs.matches('^.+D$'))

Selectors support set operations such as:

UNION: A | B

INTERSECTION: A & B

DIFFERENCE: A - B

COMPLEMENT: ~A