They work almost identically for pandas.DataFrame, and the former would work for polars.DataFrame and pyarrow.Table.
import duckdb
import polars as pl
import prql_python as prql
df = pl.DataFrame({'a': 42})
opts = prql.CompileOptions(target="sql.duckdb")
duckdb.sql(prql.compile("from df", options=opts)).pl()
Probably needs to be mentioned somewhere... (Related to #151)