PyCon 2016 in Portland, Or
hills next to breadcrumb illustration

Monday 5:10 p.m.–5:40 p.m.

Let's read code: the requests library

Susan Tan

Audience level:
Best Practices & Patterns


Imagine you’re a new engineer at a workplace who has to learn a new unfamiliar codebase. After you acquire a copy of the repo, what is your next step? How do you dissect a new unfamiliar codebase to understand its inner workings? Come see a guided walkthrough of reading the widely used python-requests project, which gets over 18,000 downloads per day and powers many of the world’s REST-based APIs.


I. This is the front-page example code that demonstrates the python-requests library. The rest of the next 30 minutes is a live walkthrough of the python-requests codebase to see how this is all implemented underneath the hood. # r = requests.get('', auth=('user', 'pass')) # r.status_code 200 # r.headers['content-type'] 'application/json; charset=utf8' # r.encoding 'utf-8' # r.text u'{"type":"User"...' # r.json() {u'private_gists': 419, u'total_private_repos': 77, …} II. How to set up the local dev environment to quickly navigate a code base. III. Time to open up directories and files. We’ll briefly explore aspects of the codebase and construct a working model of the different components of the python-requests library. IV. How does the requests library make use of & access code from its upstream repos urllib3 and chardet? VI. Summary of how "requests.get('', auth=('user', 'pass’))” works Come learn strategies on how to read new and unfamiliar code bases. We'll read through sections of the python-requests library as a case study to trace the lifecycle of a HTTP request from beginning to end.