Building an HTTP client with httpx in python

httpx is a Python library that provides a full-featured HTTP client based on the httpcore library. It is designed to be a drop-in replacement for the requests library but with improved performance, support for HTTP/1.1 and HTTP/2, and better support for asynchronous programming.

Here are some key features and aspects of the httpx module:

Installation

You can install httpx using pip:

pip install httpx

Key Features

1. Asynchronous Support:
   • httpx fully supports asynchronous programming using Python’s asyncio module.
   • It allows making asynchronous HTTP requests, which is beneficial for performance in async applications.
2. Connection Pooling:
   • httpx automatically maintains a connection pool to improve the efficiency of making multiple requests to the same host.
3. HTTP/1.1 and HTTP/2 Support:
   • It supports both HTTP/1.1 and HTTP/2 protocols.
4. WebSockets:
   • httpx supports WebSocket connections.
5. Streaming and Uploads:
   • It supports streaming of responses and uploads.
6. Automatic Decompression:
   • httpx automatically handles content compression and decompression.
7. Cookie Handling:
   • It provides a cookie jar for handling HTTP cookies.
8. Middlewares:
   • httpx supports the use of middlewares for extending and customizing its behavior.

Making a GET Request with httpx

httpx library to make a GET request to “http://www.google.es” and print information about the response.

Importing the httpx Library

import httpx

• Import Statement: Imports the httpx library, which provides an enhanced HTTP client for making requests.

Creating an httpx Client

client = httpx.Client(timeout=10.0)

• Creating an httpx Client:
• Instantiates an httpx.Client object.
• The timeout parameter is set to 10.0 seconds, specifying the maximum time the client should wait for a response.

Making a GET Request

response = client.get("http://www.google.es")

• Making a GET Request:
• Uses the get method of the httpx.Client object to make a GET request to “http://www.google.es.”
• The response is stored in the response variable.

Printing the Response Object

print(response)

• Printing the Response Object:
• Prints the entire httpx.Response object, which includes information about the HTTP response.

Printing the HTTP Status Code

print(response.status_code)

• Printing the HTTP Status Code:
• Prints the HTTP status code of the response, indicating the success or failure of the request.

Printing the Response Text

print(response.text)

• Printing the Response Text:
• Prints the content of the HTTP response as text.

import httpx

client = httpx.Client(timeout=10.0)
response = client.get("http://www.google.es")
print(response)
print(response.status_code)
print(response.text)

The provided code utilizes the httpx library to create an HTTP client, make a GET request to “http://www.google.es,” and print information about the response. This includes printing the full response object, the HTTP status code, and the response content as text. The timeout parameter ensures that the client waits a maximum of 10 seconds for a response before timing out.

Asynchronous GET Request with httpx

httpx library to make an asynchronous GET request to “http://www.google.es” and prints information about the response.

Importing the httpx Library and asyncio Module

import httpx
import asyncio

• Import Statements:
• Imports the httpx library for making HTTP requests.
• Imports the asyncio module for handling asynchronous operations.

Defining an Asynchronous Function

async def request_http1():

• Asynchronous Function:
• Defines an asynchronous function named request_http1 using the async def syntax.

Creating an httpx AsyncClient and Making an Asynchronous GET Request

async with httpx.AsyncClient() as client:
response = await client.get("http://www.google.es")

• Creating an httpx AsyncClient:
• Uses httpx.AsyncClient to create an asynchronous HTTP client within an async with context.
• Makes an asynchronous GET request to “http://www.google.es” using await client.get() and stores the response in the response variable.

Printing the Response Object and Text

print(response)
print(response.text)

• Printing Response Information:
• Prints the entire httpx.Response object, which includes information about the HTTP response.
• Prints the content of the HTTP response as text.

Printing the HTTP Version

print(response.http_version)

• Printing HTTP Version:
• Prints the HTTP version used in the response (e.g., “HTTP/1.1” or “HTTP/2”).

Running the Asynchronous Function

asyncio.run(request_http1())

• Running the Asynchronous Function:
• Uses asyncio.run to run the asynchronous function request_http1().

import httpx
import asyncio

async def request_http1():
    async with httpx.AsyncClient() as client:
        response = await client.get("http://www.google.es")
        print(response)
        print(response.text)
        print(response.http_version)
		
asyncio.run(request_http1())

The provided code demonstrates making an asynchronous GET request to “http://www.google.es” using the httpx library. The use of the async with statement and await keyword allows for asynchronous handling of the HTTP request. The code prints information about the HTTP response, including the response object, response text, and the HTTP version used. The entire asynchronous operation is executed using asyncio.run().

Asynchronous HTTP/2 GET Request with httpx

httpx library to make an asynchronous HTTP/2 GET request to “https://www.google.es” and prints information about the response.

Importing the httpx Library and asyncio Module

import httpx
import asyncio

• Import Statements:
• Imports the httpx library for making HTTP requests.
• Imports the asyncio module for handling asynchronous operations.

Defining an Asynchronous Function

async def resquest_http2():

• Asynchronous Function:
• Defines an asynchronous function named resquest_http2 using the async def syntax.

Creating an httpx AsyncClient with HTTP/2 Support

async with httpx.AsyncClient(http2=True) as client:

• Creating an httpx AsyncClient with HTTP/2:
• Uses httpx.AsyncClient to create an asynchronous HTTP client within an async with context.
• The http2=True parameter enables support for the HTTP/2 protocol.

Making an Asynchronous HTTP/2 GET Request

response = await client.get("https://www.google.es")

• Asynchronous HTTP/2 GET Request:
• Makes an asynchronous HTTP/2 GET request to “https://www.google.es” using await client.get().
• Stores the response in the response variable.

Printing the Response Object and HTTP Version

print(response)
print(response.http_version)

• Printing Response Information:
• Prints the entire httpx.Response object, which includes information about the HTTP response.
• Prints the HTTP version used in the response (e.g., “HTTP/1.1” or “HTTP/2”).

Running the Asynchronous Function

asyncio.run(resquest_http2())

• Running the Asynchronous Function:
• Uses asyncio.run to run the asynchronous function resquest_http2().

import httpx
import asyncio

async def resquest_http2():
	async with httpx.AsyncClient(http2=True) as client:
		response = await client.get("https://www.google.es")
		print(response)
		print(response.http_version)
		
asyncio.run(resquest_http2())

The provided code demonstrates making an asynchronous HTTP/2 GET request to “https://www.google.es” using the httpx library. The use of http2=True in the httpx.AsyncClient configuration enables support for the HTTP/2 protocol. The code prints information about the HTTP response, including the response object and the HTTP version used. The entire asynchronous operation is executed using asyncio.run().

Asynchronous Parallel HTTP/2 Requests with httpx and trio

httpx library to make asynchronous parallel HTTP/2 GET requests to Wikipedia URLs and stores the results in a dictionary.

Importing the httpx and trio Libraries

import httpx
import trio

• Import Statements:
• Imports the httpx library for making HTTP requests.
• Imports the trio library, an asynchronous I/O library, which is used for managing concurrent tasks.

Initializing Results Dictionary

results = {}

• Initializing Results Dictionary:
• Initializes an empty dictionary named results to store the results of the asynchronous requests.

Defining an Asynchronous Function for Fetching Results

async def fetch_result(client, url, results):
    print(url)
    results[url] = await client.get(url)

• Asynchronous Function for Fetching Results:
• Defines an asynchronous function named fetch_result.
• Takes an httpx.AsyncClient, a URL, and the results dictionary as parameters.
• Prints the URL.
• Makes an asynchronous HTTP GET request using await client.get(url) and stores the response in the results dictionary.

Defining the Main Asynchronous Function for Parallel Requests

async def main_parallel_requests():
    async with httpx.AsyncClient(http2=True) as client:
        async with trio.open_nursery() as nursery:
            for i in range(2000, 2020):
                url = f"https://en.wikipedia.org/wiki/{i}"
                nursery.start_soon(fetch_result, client, url, results)

• Main Asynchronous Function for Parallel Requests:
• Defines the main asynchronous function named main_parallel_requests.
• Creates an httpx.AsyncClient with HTTP/2 support within an async with context.
• Opens a trio nursery for managing concurrent tasks.
• Iterates through a range of years (2000 to 2019) and starts a new task (coroutine) for each Wikipedia URL using nursery.start_soon.

Running the Asynchronous Main Function with trio.run

trio.run(main_parallel_requests)

• Running the Asynchronous Main Function:
• Uses trio.run to execute the main_parallel_requests asynchronous function.

Printing the Results Dictionary

print(results)

• Printing the Results Dictionary:
• Prints the populated results dictionary after the parallel requests have been completed.

import httpx
import trio

results={}

async def fetch_result(client,url,results):
    print(url)
    results[url] = await client.get(url)
	
async def main_parallel_requests():
	async with httpx.AsyncClient(http2=True) as client:
		async with trio.open_nursery() as nursey:
			for i in range(2000,2020):
				url = f"https://en.wikipedia.org/wiki/{i}"
				nursey.start_soon(fetch_result,client,url,results)
		
trio.run(main_parallel_requests)
print(results)

The provided code demonstrates making asynchronous parallel HTTP/2 GET requests to Wikipedia URLs for a range of years (2000 to 2019) using the httpx library and managing concurrent tasks with the trio library. The results of the requests are stored in the results dictionary, and the final dictionary is printed after the requests are completed. The asynchronous nature of the code allows for concurrent execution of multiple requests.