An elegant little timeout cache decorator for python

timeout_cache.py

from functools import wraps
from time import perf_counter  # perf_counter is a highly quality timestamp

# Keys are the functions themselves, values are a tuple containing the timeout expiry
# of the cache entry, and the cached return value.
function_cache = {}


def timeout_cache(seconds: int or float):
    def check_timeout_cache(wrapped_func):

        @wraps(wrapped_func)
        def cache_or_call(*args, **kwargs):
            # default (performant) case: look for cached function, check timeout.
            try:
                timeout, ret_val = function_cache[wrapped_func]
                if perf_counter() < timeout:
                    return ret_val
            except KeyError:
                pass
            # slow case, cache miss: run function, cache the output, return output.
            ret_val = wrapped_func(*args, **kwargs)
            function_cache[wrapped_func] = (perf_counter() + seconds, ret_val)
            return ret_val

        return cache_or_call
    return check_timeout_cache


# example:
@timeout_cache(10)
def now_kinda():
    from datetime import datetime
    return datetime.now()