Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
pola-rs
GitHub Repository: pola-rs/polars
 Path: blob/main/py-polars/tests/unit/operations/namespaces/string/test_concat.py
6940 views
1
from datetime import datetime

2


3
import pytest

4


5
import polars as pl

6
from polars.testing import assert_series_equal

7


8


9
def test_str_join() -> None:

10
    s = pl.Series(["1", None, "2", None])

11
    # propagate null

12
    assert_series_equal(

13
        s.str.join("-", ignore_nulls=False), pl.Series([None], dtype=pl.String)

14
    )

15
    # ignore null

16
    assert_series_equal(s.str.join(), pl.Series(["12"]))

17


18
    # str None/null is ok

19
    s = pl.Series(["1", "None", "2", "null"])

20
    assert_series_equal(

21
        s.str.join("-", ignore_nulls=False), pl.Series(["1-None-2-null"])

22
    )

23
    assert_series_equal(s.str.join("-"), pl.Series(["1-None-2-null"]))

24


25


26
def test_str_join2() -> None:

27
    df = pl.DataFrame({"foo": [1, None, 2, None]})

28


29
    out = df.select(pl.col("foo").str.join(ignore_nulls=False))

30
    assert out.item() is None

31


32
    out = df.select(pl.col("foo").str.join())

33
    assert out.item() == "12"

34


35


36
def test_str_join_all_null() -> None:

37
    s = pl.Series([None, None, None], dtype=pl.String)

38
    assert_series_equal(

39
        s.str.join(ignore_nulls=False), pl.Series([None], dtype=pl.String)

40
    )

41
    assert_series_equal(s.str.join(ignore_nulls=True), pl.Series([""]))

42


43


44
def test_str_join_empty_list() -> None:

45
    s = pl.Series([], dtype=pl.String)

46
    assert_series_equal(s.str.join(ignore_nulls=False), pl.Series([""]))

47
    assert_series_equal(s.str.join(ignore_nulls=True), pl.Series([""]))

48


49


50
def test_str_join_empty_list2() -> None:

51
    s = pl.Series([], dtype=pl.String)

52
    df = pl.DataFrame({"foo": s})

53
    result = df.select(pl.col("foo").str.join()).item()

54
    expected = ""

55
    assert result == expected

56


57


58
def test_str_join_empty_list_agg_context() -> None:

59
    df = pl.DataFrame(data={"i": [1], "v": [None]}, schema_overrides={"v": pl.String})

60
    result = df.group_by("i").agg(pl.col("v").drop_nulls().str.join())["v"].item()

61
    expected = ""

62
    assert result == expected

63


64


65
def test_str_join_datetime() -> None:

66
    df = pl.DataFrame({"d": [datetime(2020, 1, 1), None, datetime(2022, 1, 1)]})

67
    out = df.select(pl.col("d").str.join("|", ignore_nulls=True))

68
    assert out.item() == "2020-01-01 00:00:00.000000|2022-01-01 00:00:00.000000"

69
    out = df.select(pl.col("d").str.join("|", ignore_nulls=False))

70
    assert out.item() is None

71


72


73
def test_str_concat_deprecated() -> None:

74
    s = pl.Series(["1", None, "2", None])

75
    with pytest.deprecated_call():

76
        result = s.str.concat()

77
    expected = pl.Series(["1-2"])

78
    assert_series_equal(result, expected)

79


80