Python Cookbook, 3rd Edition

Chapter 11. Network and Web Programming

This chapter is about various topics related to using Python in networked and distributed applications. Topics are split between using Python as a client to access existing services and using Python to implement networked services as a server. Common techniques for writing code involving cooperating or communicating with interpreters are also given.

11.1. Interacting with HTTP Services As a Client

Problem

You need to access various services via HTTP as a client. For example, downloading data or interacting with a REST-based API.

Solution

For simple things, it’s usually easy enough to use the urllib.request module. For example, to send a simple HTTP GET request to a remote service, do something like this:

from urllib import request, parse

# Base URL being accessed
url = 'http://httpbin.org/get'

# Dictionary of query parameters (if any)
parms = {
   'name1' : 'value1',
   'name2' : 'value2'
}

# Encode the query string
querystring = parse.urlencode(parms)

# Make a GET request and read the response
u = request.urlopen(url+'?' + querystring)
resp = u.read()

If you need to send the query parameters in the request body using a POST method, encode them and supply them as an optional argument to urlopen() like this:

from urllib import request, parse

# Base URL being accessed
url = 'http://httpbin.org/post'

# Dictionary of query parameters (if any)
parms = {
   'name1' : 'value1',
   'name2' : 'value2'
}

# Encode the query string
querystring = parse.urlencode(parms)