code: def test_df_describe() -> None:
      df = pl.DataFrame(
          {
              "a": [1.0, 2.8, 3.0],
              "b": [4, 5, None],
              "c": [True, False, True],
              "d": [None, "b", "c"],
              "e": ["usd", "eur", None],
              "f": [
                  date(2020, 1, 1),
                  date(2021, 1, 1),
                  date(2022, 1, 1),
              ],
          },
          schema_overrides={"e": pl.Categorical},
      )
  
      result = df.describe()
      print(result)
      expected = pl.DataFrame(
          {
              "describe": [
                  "count",
                  "null_count",
                  "mean",
                  "std",
                  "min",
                  "25%",
                  "50%",
                  "75%",
                  "max",
              ],
              "a": [
                  3.0,
                  0.0,
                  2.2666666666666666,
                  1.1015141094572205,
                  1.0,
                  2.8,
                  2.8,
                  3.0,
                  3.0,
              ],
              "b": [
                  2.0,
                  1.0,
                  4.5,
                  0.7071067811865476,
                  4.0,
                  4.0,
                  5.0,
                  5.0,
                  5.0,
              ],
              "c": [
                  "3",
                  "0",
                  None,
                  None,
                  "False",
                  None,
                  None,
                  None,
                  "True",
              ],
              "d": ["2", "1", None, None, "b", None, None, None, "c"],
              "e": ["2", "1", None, None, None, None, None, None, None],
              "f": [
                  "3",
                  "0",
                  None,
                  None,
                  "2020-01-01",
                  None,
                  None,
                  None,
                  "2022-01-01",
              ],
          }
      )
      assert_frame_equal(result, expected)
  
file_path: polars/py-polars/tests/unit/dataframe/test_describe.py
imports: from __future__ import annotations
  from datetime import date
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 1 for calling a global function with example usage: test_df_describe() without return types