How to Convert Strings to Types in Python Using TypeVar

from typing import TypeVar, Optional

T = TypeVar("T")

def convert_data(value: str, target_type: type[T]) -> Optional[T]:
    """Convert string value to target type; return None on failure."""
    try:
        if target_type is int:
            return int(value)
        elif target_type is float:
            return float(value)
        elif target_type is bool:
            return value.lower() in ("true", "1", "yes")
        elif target_type is str:
            return value
        return None
    except (ValueError, TypeError):
        return None


if __name__ == "__main__":
    # Simple test cases to demonstrate the converter
    print(convert_data("42", int))        # 42
    print(convert_data("3.14", float))    # 3.14
    print(convert_data("true", bool))     # True
    print(convert_data("hello", str))     # hello
    print(convert_data("abc", int))       # None
    print(convert_data("not-bool", bool)) # False