Sending HTTP Requests Using the Requests Library in Python

In modern web programming, HTTP requests are the primary means of communication with servers. Python provides a very powerful library – <span>requests</span>, which makes sending HTTP requests simple and intuitive. This article will detail how to use the <span>requests</span> library to send various types of HTTP requests, along with corresponding code examples.

1. Installing the Requests Library

Before we begin, you need to ensure that the <span>requests</span> library is installed. If you haven’t installed it yet, you can do so with the following command:

pip install requests

2. Sending a GET Request

A GET request is used to retrieve data from a server. Here is a simple example demonstrating how to send a GET request using the <span>requests</span> library.

import requests
# Target URL
url = 'https://jsonplaceholder.typicode.com/posts/1'
# Send GET request
response = requests.get(url)
# Print response status code and content
print('Status Code:', response.status_code)
print('Response Content:', response.json())

Explanation:

• First, we import the <span>requests</span> module.
• Then we define the URL to request.
• Using the <span>requests.get()</span> method, we send a GET request to that URL and store the returned response in the variable <span>response</span>.
• Finally, we print the response’s status code and content. The status code helps us determine if the request was successful, while the content is the data returned by the server.

3. Sending a POST Request

A POST request is typically used to submit data to a server. In this example, we will submit some JSON data to the server.

import requests
# Target URL
url = 'https://jsonplaceholder.typicode.com/posts'
# Data to submit (in dictionary format)
data = {    'title': 'foo',    'body': 'bar',    'userId': 1,}
# Send POST request
response = requests.post(url, json=data)
# Print response status code and content
print('Status Code:', response.status_code)
print('Response Content:', response.json())

Explanation:

• We also import the <span>requests</span> module and define the target URL.
• We create a dictionary to represent the data to be submitted.
• Using the <span>requests.post()</span> method, we pass the data in JSON format to the server and receive the returned response.
• Finally, we print the status code and the returned data.

4. Adding Request Headers

Sometimes we need to add custom request headers, such as setting a user agent or authentication information. Here’s how to add request headers:

import requests
url = 'https://jsonplaceholder.typicode.com/posts'
headers = {    'Content-Type': 'application/json',    'User-Agent': 'my-app/0.0.1'}
data = {    'title': 'foo',    'body': 'bar',    'userId': 1,}
response = requests.post(url, headers=headers, json=data)
print('Status Code:', response.status_code)
print('Response Content:', response.json())

Explanation:

• In this example, we create a dictionary containing custom header information, which we then pass as parameters when calling the POST method.

5. Error Handling

In practical applications, requests may fail, so we should handle errors. For example, we can check for exceptions and output corresponding information:

import requests
try:    url = "https://jsonplaceholder.typicode.com/posts/100"
    # Attempt to make a GET request     response = requests.get(url)
    # Check if successful (200 OK)    if response.status_code == 200:        print("Successfully retrieved data:", response.json())    else:        print("Error occurred, status code:", response.status_code)
except Exception as e:    print("An exception occurred:", str(e))

Explanation:

• We use a try-except block to catch potential exceptions, such as network issues. We can also provide timely feedback on errors when a non-200 status is detected.

Conclusion

This article introduced how to use Python’s <span>requests</span> library to initiate different types of HTTP requests, including GET and POST. It also demonstrated how to add custom request headers and basic error handling methods. This foundational knowledge will help you better interact with web services and lay a solid foundation for your projects. I hope this article is helpful to you.