Async coroutine support

[lrq3000]

Add asynchronized coroutine support in tqdm as proposed in #65.

Code thank's to @aplavin, from here and here.

This code wasn't tested out, can someone devise an example case? (I'm inexperienced with Python coroutines :S).

[codecov-io]

Current coverage is 96.86%

Merging #91 into master will decrease coverage by -3.14% as of f0abb3d

@@            master     #91   diff @@
======================================
  Files            5       5       
  Stmts          239     255    +16
  Branches        49      49       
  Methods          0       0       
======================================
+ Hit            239     247     +8
  Partial          0       0       
- Missed           0       8     +8

Review entire Coverage Diff as of f0abb3d

Powered by Codecov. Updated on successful CI builds.

[sametmax]

import asyncio

from tqdm import tqdm

async def main():
    async for x in tqdm(range(10), miniters=0):
        do_stuff()

loop = asyncio.get_event_loop()
loo.run_until_complete(main())

How ever, there is much more to consider to unit test it:

• aiter is only awailable on 3.5 and requires async/await, which are SyntaxErrors on earlier versions. So the test must be in a separate files, and ignored by the test runner for python 3.4-.

• anext should probably do yield from self.iterable instead of next(self.iterable) in case the iterable itself is asynchronous.

• if you want to unit test it, you'll need to start the eventloop as a setUp and stop it as a tearDown. Libs like pytest-asyncio do it automatically for you.

• if you need to mock an awaitable, do:

  import asyncio
  
  class AMock(Mock):
  
      async def __call__(self, *args, **kwargs):
          result = super().__call__(self, *args, **kwargs)
          async def coroutine():
              return result
          return asyncio.ensure_future(coro())
  

If that works well, you can also make an async context manager : https://docs.python.org/3/reference/datamodel.html#asynchronous-context-managers

[lrq3000]

Wow thank you very much sametmax, this sure helps a lot ! I'll train a bit
with toy examples following your guidelines before making a unit test, and
ill change next() for the more pythonic syntax in my PR :)
Le 21 Jan. 2016 18:44, "sametmax" notifications@github.com a écrit :

import asyncio

from tqdm import tqdm

async def main():
async for x in tqdm(range(10)):
print(x)

loop = asyncio.get_event_loop()
loo.run_until_complete()

How ever, there is much more to consider to unit test it:

• aiter is only awailable on 3.5 and requires async/await, which are
  SyntaxErrors on earlier versions. So the test must be in a separate files,
  and ignored by the test runner for python 3.4-.

• anext should probably do "yield from self.iterable" instead of
  next() in case the iterable itself is asyncronous.

• if you want to unit test it, you'll need to start the eventloop as a
  setUp and stop it as a tearDown. Libs like pytest-asyncio do it

  automatically for you.

  if you need to mock an awaitable, do:

  import asyncio

  class AMock(Mock):

  async def call(self, _args, *_kwargs):
  result = super().call(self, _args, *_kwargs)
  async def coroutine():
  return result
  return asyncio.ensure_future(coro())

—
Reply to this email directly or view it on GitHub
#91 (comment).

[AlJohri]

Just ran into this issue myself. Bumping this PR.

TypeError: 'async for' requires an object with __aiter__ method, got tqdm

[AlJohri]

I believe this one should not be a coroutine.

[AlJohri]

This works for me:

from tqdm.auto import tqdm

def __aiter__(self):
    return self

async def __anext__(self):
    try:
        self.update()
        return await self.iterable.__anext__()
    except StopIteration:
        self.close()
        raise StopAsyncIteration
tqdm.__aiter__ = __aiter__
tqdm.__anext__ = __anext__

################################################

async for row in tqdm(con.cursor('SELECT * FROM pageviews ORDER BY user_id')):
    pass

[casperdcl]

ah nice, I suppose I should take over. @AlJohri could you write a unit test?

[malarinv]

@casperdcl will this be merged soon?

[codecov-commenter]

Codecov Report

Merging #91 into master will decrease coverage by 0.70%.
The diff coverage is 26.66%.

@@            Coverage Diff             @@
##           master      #91      +/-   ##
==========================================
- Coverage   87.16%   86.46%   -0.71%     
==========================================
  Files          21       21              
  Lines        1278     1293      +15     
  Branches      217      218       +1     
==========================================
+ Hits         1114     1118       +4     
- Misses        143      154      +11     
  Partials       21       21