Cannot convert strings to category/factor/enum

[david-cortes]

I want to have a query result with categorical columns being encoded as pandas 'Category' or R 'factor' type for better memory efficiency. Trying to cast a string (python 'object' or R 'character' types) in a query does not produce the desired result:

import pandas as pd
df = pd.DataFrame({"col1" : ["a","b","c"]})
import duckdb
duckdb.query("select col1::enum from df").to_df()

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
<ipython-input-2-81ef41169f6a> in <module>
      2 df = pd.DataFrame({"col1" : ["a","b","c"]})
      3 import duckdb
----> 4 duckdb.query("select col1::enum from df").to_df()

RuntimeError: Catalog Error: Type with name enum does not exist!
Did you mean "null"?

I would have to manually create a type and assign it there, which is extremely inconvenient and pollutes my duckdb namespace:

import duckdb
duckdb.query("create type my_col_type as enum('a', 'b', 'c');")
import pandas as pd
df = pd.DataFrame({"col1" : ["a","b","c"]})
duckdb.query("select col1::my_col_type from df").to_df()

[Alex-Monahan]

Today, this behavior is expected, but it is on the roadmap to enable the syntax you are interested in!

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 30 days.

[david-cortes]

Still relevant.

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 30 days.