Introduction To Asynchronous Programming With Python

The slide deck for this presentation is accessible here.

This repository contains the code examples that go along with the Google slide deck for the presentation. The examples progress one after the other from a simple synchronous app that just runs a time delayed task to an asynchronous one that gets web pages using two workers to get web pages concurrently.

Installation

It's recommended to use a Python virtual environment to install the necessary modules and run the example programs. I use pyenv to make a version of Python available in the project directory. The examples were built using Python version 3.9.5.

Here's the commands using pyenv to get the examples running in Mac or Linux:

$ pyenv local 3.9.5
$ python -m venv .venv
$ source .venv/bin/activate
$ (.venv) pip install --upgrade pip
$ (.venv) pip install -r requirements.txt

Example Programs

• example_1.py - This program demonstrates a synchronous approach to accomplishing tasks. The worker can't delegate any tasks and completes them all one after another.
• example_2.py - This program demonstrates a synchronous approach to accomplishing tasks. The worker can't delegate any tasks and completes them all one after another. In this version there is a second worker created, but the two workers aren't cooperating with each other.
• example_3.py - This program demonstrates a synchronous approach to accomplishing tasks. In this version there is a second worker created, and the workers can delegate back to the control loop to cooperate with each other, but there isn't any net benefit because the tasks are still running synchronously.
• example_4.py - This program demonstrates a asynchronous approach to accomplishing tasks. In this version there is a second worker created, and the workers can delegate back to the control loop to cooperate with each other. In this version the tasks are asynchronous, so the workers run concurrently.
• example_5.py - This program demonstrates a synchronous approach to accomplishing tasks. In this version there is a second worker created, and the workers can delegate back to the control loop to cooperate with each other, but there isn't any net benefit because the tasks are still running synchronously. The tasks for this demo are getting the contents of webpages.
• example_6.py - This program demonstrates a asynchronous approach to accomplishing tasks. In this version there is a second worker created, and the workers can delegate back to the control loop to cooperate with each other. In this version the tasks are asynchronous, so the workers run concurrently. The tasks for this demo are getting the contents of webpages.
• example_7.py - This is a bonus example program demonstrating a asynchronous approach to accomplishing tasks. In this version there is a second worker created, and the workers can delegate back to the control loop to cooperate with each other. In this version the tasks are asynchronous, so the workers run concurrently. The tasks for this demo are getting the contents of webpages and reading files