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@coordt
Last active May 7, 2023 13:41

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  1. coordt revised this gist May 7, 2023. 1 changed file with 82 additions and 0 deletions.
    82 changes: 82 additions & 0 deletions test_autocast.py
    Original file line number Diff line number Diff line change
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    """Tests for the autocast module."""
    import pytest
    from pytest import param

    from archeion import autocast


    @pytest.mark.parametrize(
    "value, expected",
    [
    param("true", True, id="true"),
    param("false", False, id="false"),
    param("True", True, id="True"),
    param("False", False, id="False"),
    ],
    )
    def test_boolify_valid(value: str, expected: bool) -> None:
    """Test the boolify function."""
    assert autocast.boolify(value) == expected


    @pytest.mark.parametrize(
    "value",
    [
    param(1, id="int"),
    param("string", id="str"),
    ],
    )
    def test_boolify_invalid(value):
    """Test the boolify function."""
    with pytest.raises(ValueError):
    autocast.boolify(value)


    def test_noneify():
    """noneify should return None if the string is None."""
    assert autocast.noneify("None") is None
    with pytest.raises(ValueError):
    autocast.noneify("0")


    @pytest.mark.parametrize(
    "value,expected",
    [
    param("1,2,3,4", [1, 2, 3, 4], id="int"),
    param("s,t,r", ["s", "t", "r"], id="str"),
    param("1.1,2,3.14", [1.1, 2.0, 3.14], id="float"),
    param("True,False,true,false", [True, False, True, False], id="bool"),
    param("None,None,None", [None, None, None], id="none"),
    ],
    )
    def test_listify_valid(value, expected):
    """Test the listify function."""
    assert autocast.listify(value) == expected


    def test_listify_invalid():
    """Every element of the list should be the same type."""
    with pytest.raises(TypeError):
    autocast.listify("True,1,None")

    with pytest.raises(ValueError):
    autocast.listify("I am not a list")


    @pytest.mark.parametrize(
    "value,expected",
    [
    param("true", True, id="true"),
    param("false", False, id="false"),
    param("True", True, id="True"),
    param("False", False, id="False"),
    param("1,2,3,4", [1, 2, 3, 4], id="int-list"),
    param("s,t,r", ["s", "t", "r"], id="str-list"),
    param("1", 1, id="int"),
    param("1.0", 1.0, id="float"),
    param(1, 1, id="real-int"),
    ],
    )
    def test_autocast_value(value, expected):
    """Test basic functionality of autocast_value."""
    assert autocast.autocast_value(value) == expected
  2. coordt created this gist May 7, 2023.
    80 changes: 80 additions & 0 deletions autocast.py
    Original file line number Diff line number Diff line change
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    """
    Automatically detect the true Python type of a string and cast it to the correct type.
    Based on https://github.com/cgreer/cgAutoCast/blob/master/cgAutoCast.py
    """

    import contextlib
    from typing import Any


    def boolify(s: str) -> bool:
    """Convert a string to a boolean."""
    if s in {"True", "true"}:
    return True
    if s in {"False", "false"}:
    return False
    raise ValueError("Not Boolean Value!")


    def noneify(s: str) -> None:
    """Convert a string to None."""
    if s == "None":
    return None
    raise ValueError("Not None Value!")


    def listify(s: str) -> list:
    """
    Convert a string representation of a list into list of homogenous basic types.
    Type of elements in list is determined via first element. Successive elements are
    cast to that type.
    Args:
    s: String representation of a list.
    Raises:
    ValueError: If string does not represent a list.
    TypeError: If string does not represent a list of homogenous basic types.
    Returns:
    List of homogenous basic types.
    """
    if "," not in s:
    raise ValueError("Not a List")

    # derive the type of the variable
    str_list = s.split(",")
    element_caster = str
    for caster in (boolify, int, float, noneify, element_caster):
    with contextlib.suppress(ValueError):
    caster(str_list[0]) # type: ignore[operator]
    element_caster = caster # type: ignore[assignment]
    break
    # cast all elements
    try:
    return [element_caster(x) for x in str_list]
    except ValueError as e:
    raise TypeError("Autocasted list must be all same type") from e


    def autocast_value(var: Any) -> Any:
    """
    Guess the string representation of the variable's type.
    Args:
    var: Value to autocast.
    Returns:
    The autocasted value.
    """
    if not isinstance(var, str): # don't need to guess non-string types
    return var

    # guess string representation of var
    for caster in (boolify, int, float, noneify, listify):
    with contextlib.suppress(ValueError):
    return caster(var) # type: ignore[operator]

    return var