requirements.txt

#
# This file is autogenerated by pip-compile with Python 3.12
# by the following command:
#
#    pip-compile
#
iniconfig==2.0.0
    # via pytest
packaging==24.1
    # via pytest
pluggy==1.5.0
    # via pytest
polars==1.0.0
    # via -r requirements.in
pytest==8.2.2
    # via -r requirements.in

test_polars.py

import io

import polars as pl
import pytest

fixture = """\
first_name,last_name
josé,österlung
additional,content
"""


@pytest.mark.parametrize(
    ("k",),
    [
        (50,),
        # raises OSError: failed to write whole buffer
        pytest.param(500, marks=pytest.mark.xfail(raises=OSError)),
    ],
)
def test_textwrapper(k: int):
    long_fixture = fixture * k
    fixture_bytes = io.BytesIO(long_fixture.encode("latin1"))
    wrapper = io.TextIOWrapper(fixture_bytes, "latin1", "replace")
    pl.read_csv(wrapper)