import re
import timeit
from typing import List, Dict, Any, Union

def old_format_annotation(annotation):
    if getattr(annotation, "__module__", None) == "typing":
        def repl(match):
            text = match.group()
            return text.removeprefix("typing.")
        return re.sub(r"[\w\.]+", repl, repr(annotation))
    return repr(annotation)

def new_format_annotation(annotation):
    if getattr(annotation, "__module__", None) == "typing":
        return (repr(annotation)
                .replace(".typing.", "@TYPING@")
                .replace("typing.", "")
                .replace("@TYPING@", ".typing."))
    return repr(annotation)

old_time = timeit.timeit(lambda: old_format_annotation(Union[List[str], Dict[str, Any]]), number=100_000)
new_time = timeit.timeit(lambda: new_format_annotation(Union[List[str], Dict[str, Any]]), number=100_000)

print(f"Old version (re.sub): {old_time:.6f}s")
print(f"New version (.replace()): {new_time:.6f}s")
print(f"Difference: {old_time / new_time:.2f}x")