I believe this implementation is broken if you enter/aenter the class twice before aexit'ing (share instance with multiple classes). The lock should be from enter/aenter through exit/aexit. This would also mean that you can't use the sync lock in exit with aexit

Use async with self._alock: instead of await self_alock:

Hi,
as reported in the Debian bug tracking system ratelimiter does not work with python3.11:

Python 3.11.1 (main, Dec  7 2022, 08:49:13) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ratelimiter
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/andreas/debian-maintain/salsa/python-team/packages/python-ratelimiter/ratelimiter.py", line 36, in <module>
    class RateLimiter(object):
  File "/home/andreas/debian-maintain/salsa/python-team/packages/python-ratelimiter/ratelimiter.py", line 127, in RateLimiter    
    __aexit__ = asyncio.coroutine(__exit__)
                ^^^^^^^^^^^^^^^^^
AttributeError: module 'asyncio' has no attribute 'coroutine'. Did you mean: 'coroutines'?

Kind regards, Andreas.

Not that exec() is a huge problem in this context, but perhaps a more elegant way to support Python < 3.5 would be to move __aenter__ into a different module and import the module on runtime. E.g.

import sys

if sys.version_info < (3, 5):
    raise ImportError("Only support python versions >= 3.5")

import time
import asyncio

async def __aenter__(self):
    if self._alock is None:
        self._init_async_lock()

    with await self._alock:
        # We want to ensure that no more than max_calls were run in the allowed
        # period. For this, we store the last timestamps of each call and run
        # the rate verification upon each __enter__ call.
        if len(self.calls) >= self.max_calls:
            until = time.time() + self.period - self._timespan
            if self.callback:
                asyncio.ensure_future(self.callback(until))
            sleeptime = until - time.time()
            if sleeptime > 0:
                await asyncio.sleep(sleeptime)
        return self

and

class RateLimiter(object):
    """Provides rate limiting for an operation with a configurable number of
    requests for a time period.
    """
    # snip

    if PY35:
        import _async
        __aenter__ = _async.__aenter__
        __aexit__ = asyncio.coroutine(__exit__)

If you have the time to merge PRs and make releases, please email me at the address on my profile. Please include any links to existing projects you maintain.

If you are a user of ratelimiter looking for a maintained alternative, I recommend rush

I think those lines are not useful

        self._alock = None

        # Lock to protect creation of self._alock
        self._init_lock = threading.Lock()

See python-astrodynamics/spacetrack#38

The lock should be not be created there's not an event loop.

I have a function that uses the requests library that I am decorating with a callback. The callback seems to be triggered more frequently than one would expect. The behavior works as expected when the decorated function returns a string.

import requests
from ratelimiter import RateLimiter


def callback_message(until):
    print('Rate limit reached, sleeping')


@RateLimiter(max_calls=30, period=15, callback=callback_message)
def thing1():
    return requests.get("https://www.google.com")


@RateLimiter(max_calls=30, period=15, callback=callback_message)
def thing2():
    return "thing2"


print("Testing with requests")
for i in range(100):
    if i % 10 == 0:
        print(i)
    thing1()

print("Testing with simple function")
for i in range(100):
    if i % 10 == 0:
        print(i)
    thing2()

This is the output:

Testing with requests
0
10
20
30
Rate limit reached, sleeping
Rate limit reached, sleeping
40
Rate limit reached, sleeping
50
60
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping
70
Rate limit reached, sleeping
Rate limit reached, sleeping
80
Rate limit reached, sleeping
Rate limit reached, sleeping
90
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping
Rate limit reached, sleeping

Testing with simple functions
0
10
20
30
Rate limit reached, sleeping
40
50
60
Rate limit reached, sleeping
70
80
90
Rate limit reached, sleeping

Our project currently uses ratelimiter-1.2.0.post0, the latest version on PyPI.

Python 3.8 has been released and we're adding a py28 CI test for our project, which resulted in the following warning:

  /home/travis/virtualenv/python3.8.0/lib/python3.8/site-packages/ratelimiter.py:127: DeprecationWarning: "@coroutine" decorator is deprecated since Python 3.8, use "async def" instead
    __aexit__ = asyncio.coroutine(__exit__)

While the master branch has unreleased commits that weren't in the version we're testing, I believe the warning would still occur on the latest master commit at the following line:

Is it possible to update the code to no longer create the warning and release a new version to PyPI with the update?

Yo

While creating a Debian package for ratelimiter (as described on https://bugs.debian.org/880661), I found that the non-empty files in tests/ are missing, and that only one of the two README files (which appear to have diverged) are provided.

Please consider adding the tests via MANIFEST.in (eg. as described on stackoverflow), and having one up-to-date README that is shipped the same way.

The algorithm will always wait too much.

import time
from ratelimiter import RateLimiter

rate_limiter = RateLimiter(max_calls=1, period=1)

start = time.time()
for i in range(3):
    with rate_limiter:
        print("%.02f" % (time.time()  - start))
        time.sleep(1)

outputs

0.00
2.00
4.01

I would expect it to output 0 1 2

I have had issues installing this package with pip due to the presence of non-UTF8 characters in README.rst. This is for version 1.2.0.post0. Specifically, the quote marks around 'LICENSE' and 'AS IS' are the italicised variety and apparently non-standard.