Flatten outputs for chained boolean operations where possible Add special-case handling to flatten the data structure when chaining multiple AND/OR together; for example, make f_and(f_and(x, y), z) work approximately in the same way as f_and(x, y, z). The goal here is to avoid a stack overflow when using a pattern which can chain a large number of futures. Previously, an overflow could start to happen if the chain was a few hundred futures deep, since each future's completion callback would set the result on the next future which would invoke another completion callback and so on throughout the chain. Fixes #320
A library of composable Python executors and futures.
This library is intended for use with the concurrent.futures module. It includes a collection of Executor implementations in order to extend the behavior of Future objects.
concurrent.futures with asyncioSee the API documentation for detailed information on usage.
This example combines the map and retry executors to create futures for HTTP requests running concurrently, decoding JSON responses within the future and retrying on error.
import requests from concurrent.futures import as_completed from more_executors import Executors def get_json(response): response.raise_for_status() return (response.url, response.json()) def fetch_urls(urls): # Configure an executor: # - run up to 4 requests concurrently, in separate threads # - run get_json on each response # - retry up to several minutes on any errors executor = Executors.\ thread_pool(max_workers=4).\ with_map(get_json).\ with_retry() # Submit requests for each given URL futures = [executor.submit(requests.get, url) for url in urls] # Futures API works as normal; we can block on the completed # futures and map/retry happens implicitly for future in as_completed(futures): (url, data) = future.result() do_something(url, data)
virtualenv and pip may be used to locally install this project from source:
virtualenv ~/dev/python . ~/dev/python/bin/activate git clone https://github.com/rohanpm/more-executors cd more-executors pip install --editable .
Autotests may be run with pytest:
pip install -r test-requirements.txt py.test
Submit pull requests against https://github.com/rohanpm/more-executors.
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.