How to use httpx, a web client for Python

The httpx package for Python is an excellent and flexible module for interacting with HTTP.
13 readers like this
13 readers like this
Digital creative of a browser on the internet

The httpx package for Python is a sophisticated web client. Once you install it, you can use it to get data from websites. As usual, the easiest way to install it is with the pip utility:

$ python -m pip install httpx --user

To use it, import it into a Python script, and then use the .get function to fetch data from a web address:

import httpx
result = httpx.get("https://httpbin.org/get?hello=world")
result.json()["args"]

Here's the output from that simple script:

    {'hello': 'world'}

HTTP response

By default, httpx will not raise errors on a non-200 status. 

Try this code:

result = httpx.get("https://httpbin.org/status/404")
result

The result:

    <Response [404 NOT FOUND]>

It's possible to raise a response explicitly. Add this exception handler:

try:
    result.raise_for_status()
except Exception as exc:
    print("woops", exc)

Here's the result:

    woops Client error '404 NOT FOUND' for url 'https://httpbin.org/status/404'
    For more information check: https://httpstatuses.com/404

Custom client

It is worthwhile to use a custom client for anything but the simplest script. Aside from nice performance improvements, such as connection pooling, this is a good place to configure the client.

For example, you can set a custom base URL:

client = httpx.Client(base_url="https://httpbin.org")
result = client.get("/get?source=custom-client")
result.json()["args"]

Sample output:

    {'source': 'custom-client'}

This is useful for a typical scenario where you use the client to talk to a specific server. For example, using both base_url and auth, you can build a nice abstraction for an authenticated client:

client = httpx.Client(
    base_url="https://httpbin.org",
    auth=("good_person", "secret_password"),
)
result = client.get("/basic-auth/good_person/secret_password")
result.json()

Output:

    {'authenticated': True, 'user': 'good_person'}

One of the nicer things you can use this for is constructing the client at a top-level "main" function and then passing it around. This lets other functions use the client and lets them get unit-tested with a client connected to a local WSGI app.

def get_user_name(client):
    result = client.get("/basic-auth/good_person/secret_password")
    return result.json()["user"]

get_user_name(client)
    'good_person'

def application(environ, start_response):
    start_response('200 OK', [('Content-Type', 'application/json')])
    return [b'{"user": "pretty_good_person"}']
fake_client = httpx.Client(app=application, base_url="https://fake-server")
get_user_name(fake_client)

Output:

    'pretty_good_person'

Try httpx

Visit python-httpx.org for more information, documentation, and tutorials. I've found it to be an excellent and flexible module for interacting with HTTP. Give it a try and see what it can do for you.

Tags
Moshe sitting down, head slightly to the side. His t-shirt has Guardians of the Galaxy silhoutes against a background of sound visualization bars.
Moshe has been involved in the Linux community since 1998, helping in Linux "installation parties". He has been programming Python since 1999, and has contributed to the core Python interpreter. Moshe has been a DevOps/SRE since before those terms existed, caring deeply about software reliability, build reproducibility and other such things.

Comments are closed.

Creative Commons LicenseThis work is licensed under a Creative Commons Attribution-Share Alike 4.0 International License.