primitive_type.converter 源代码

"""A quick and simple converter to convert the type of an object."""

import re

from beartype import beartype
from primitive_type.types import Primitive




class ConvertError(TypeError):
    """An exception should happens when conversion failed."""

    pass





@beartype
def get_primitive_object(
    val: Primitive, obj_type: type[Primitive] = None
) -> Primitive:
    """Get a primitive object from a given value.

    :param val: The given value wants to be converted.
    :param obj_type: The target type of object that finally converted out. Default to :obj:`None` as disabled.

    :return:
        * :class:`str` -- If given value is a normal string, or convert to if type specified.
        * :class:`int` -- The origin object or convert to.
        * :class:`float` -- The origin object or convert to.
        * :class:`bool` -- The origin object or convert to.
        * :obj:`None` -- Only when given value is :obj:`None`.
    """
    obj_type_required: bool = obj_type is not None

    if val is None:
        if obj_type_required:
            raise TypeError(
                "Given value is None, could not convert to other type!"
            )
        return None

    if not obj_type_required:
        if not isinstance(val, str):
            return val

        val_lower = val.lower()
        if val_lower == "true":
            return True
        if val_lower == "false":
            return False

        if re.fullmatch(r"[+-]?\d+", val):
            return int(val)

        if re.fullmatch(r"[+-]?(\d+(\.\d*)?|\.\d+)([eE][+-]?\d+)?", val):
            return float(val)

        return val

    try:
        if obj_type is str:
            return str(val)

        if obj_type is bool:
            if isinstance(val, str):
                return val.lower() == "true"
            if isinstance(val, (int, float)):
                return val > 0
            return bool(val)

        if obj_type is int:
            return int(float(val)) if isinstance(val, str) else int(val)

        if obj_type is float:
            return float(val)

    except (ValueError, TypeError, SyntaxError):
        raise ConvertError(f"Could not convert '{val}' to type '{obj_type}'.")

    return val





def get_str_object(val: Primitive) -> str:
    """Get a string object from a given value.

    :param val: The given value wants to be converted.

    :return: A string object.
    """
    return get_primitive_object(val, str)  # ty: ignore[invalid-return-type]





def get_int_object(val: Primitive) -> int:
    """Get an integer object from a given value.

    :param val: The given value wants to be converted.

    :return: An integer object.
    """
    return get_primitive_object(val, int)  # ty: ignore[invalid-return-type]





def get_float_object(val: Primitive) -> float:
    """Get a float object from a given value.

    :param val: The given value wants to be converted.

    :return: A float object.
    """
    return get_primitive_object(val, float)  # ty: ignore[invalid-return-type]





def get_bool_object(val: Primitive) -> bool:
    """Get a boolean object from a given value.

    :param val: The given value wants to be converted.

    :return: A bool object.
    """
    return get_primitive_object(val, bool)  # ty: ignore[invalid-return-type]