APIs (Application Programming Interfaces) are the bridges that allow different software systems to communicate with each other.

pip install requests

import requests
import json


url = "https://reqres.in/api/users?page=2"
headers = {
    "Accept": "application/json",  # Specify the type of response you want
    "User-Agent": "MyApp/1.0"  # Identify your application
}

try:
    response = requests.get(url, headers=headers, timeout=10)

    # Raise an error for bad responses
    response.raise_for_status()

    data = response.json()  # Parse JSON response


    d1 = data # Extract the 'data' field from the JSON response 
    print(d1)  # Print the extracted data

    # Pretty print the JSON response
    print(json.dumps(data, indent=4))

except requests.exceptions.RequestException as e:
    print(f"An error occurred: {e}")
    


# The above code sends a GET request to the specified URL, retrieves the response, and prints the data in a formatted manner.
# It also handles any potential errors that may occur during the request.

import requests

payload = {"name": "test", "salary": "123", "age": "23"}
headers = {
    'User-Agent': 'nginx/1.21.6',
    'Accept': '*/*',
    'Cache-Control': 'no-cache',
    'Connection': 'keep-alive',
    'Content-Type': 'application/json'
}

try:
    # Make the POST request
    response = requests.post('https://dummy.restapiexample.com/api/v1/create', json=payload, headers=headers)
    
    # Raise an error for bad responses
    response.raise_for_status()
    
    # If the request is successful, parse the JSON response
    data = response.json()
    
    # Print the response data
    print("Resource created successfully!")
    print(data)

except requests.exceptions.RequestException as e:
    print(f"An error occurred: {e}")

Understanding Custom Headers

Custom headers can be crucial when interacting with APIs, especially those requiring authentication or specific content types. Let’s break down the headers used in the POST request:

User-Agent: Identifies the client software making the request. This can be important for compatibility and analytics purposes.
Accept: Tells the server what media types the client can handle. Here, */* indicates that any media type is acceptable.
Cache-Control: Manages caching behavior. no-cache means that the client wants a fresh copy of the resource.
Connection: keep-alive keeps the connection open, allowing for more efficient communication.
Content-Type: Indicates the format of the data being sent. In our example, it’s JSON.

HTTP response status codes:

Code	Status	Description
1xx	Informational
100	Continue	The server has received the request headers and the client should proceed to send the request body.
101	Switching Protocols	The requester has asked the server to switch protocols, and the server is acknowledging that it will do so.
2xx	Success
200	OK	The request was successful, and the server returned the requested resource.
201	Created	The request was successful, and a new resource was created as a result.
202	Accepted	The request has been accepted for processing, but the processing is not yet complete.
204	No Content	The request was successful, but there is no content to send in the response.
3xx	Redirection
301	Moved Permanently	The requested resource has been permanently moved to a new URL.
302	Found	The requested resource is temporarily located at a different URL.
304	Not Modified	The resource has not been modified since the last request, so the client can use the cached version.
4xx	Client Errors
400	Bad Request	The server could not understand the request due to invalid syntax.
401	Unauthorized	The client must authenticate itself to get the requested response.
403	Forbidden	The client does not have permission to access the requested resource.
404	Not Found	The server could not find the requested resource.
405	Method Not Allowed	The request method is not supported for the requested resource.
408	Request Timeout	The server timed out waiting for the request.
409	Conflict	The request could not be processed because of a conflict in the request, such as an edit conflict.
429	Too Many Requests	The user has sent too many requests in a given amount of time ("rate limiting").
5xx	Server Errors
500	Internal Server Error	The server encountered an error and could not complete the request.
501	Not Implemented	The server does not support the functionality required to fulfill the request.
502	Bad Gateway	The server received an invalid response from the upstream server.
503	Service Unavailable	The server is not ready to handle the request, usually due to maintenance or overload.
504	Gateway Timeout	The server, while acting as a gateway, did not receive a timely response from the upstream server.

This table summarizes the most common HTTP status codes and their meanings.

import json
def jprint(obj):
    text = json.dumps(obj, sort_keys=False, indent=2)
    print(text)

json.dumps() Function: This function converts a Python object (obj) into a JSON-formatted string.

sort_keys=False: This argument controls whether the keys in the JSON output should be sorted. By setting it to False, the keys will appear in the order they were inserted into the original Python object.

Useful exceptions error

except requests.exceptions.Timeout:
    print("The request timed out. Please try again later.")
except requests.exceptions.TooManyRedirects:
    print("Too many redirects. Check the URL and try again.")
except requests.exceptions.RequestException as e:
    print(f"An error occurred: {e}")
except json.JSONDecodeError:
    print("Failed to decode JSON response. Please check the server response.")
except requests.exceptions.HTTPError as err:
    if err.response.status_code == 400:
        print("Bad Request: The server could not understand the request.")
    elif err.response.status_code == 401:
        print("Unauthorized: Access is denied due to invalid credentials.")
    elif err.response.status_code == 403:
        print("Forbidden: You do not have permission to access this resource.")
    elif err.response.status_code == 404:
        print("Not Found: The requested resource could not be found.")
    elif err.response.status_code == 500:
        print("Internal Server Error: The server encountered an error and could not complete your request.")
    else:
        print(f"HTTP error occurred: {err}")
except requests.exceptions.ConnectionError:
    print("Connection error: Please check your internet connection.")

except Exception as e:
    print(f"An unexpected error occurred: {e}")

`urllib` library

Python की urllib लाइब्रेरी एक built-in (इन-बिल्ट) लाइब्रेरी है जो web से data को access करने के लिए इस्तेमाल होती है। इसे आमतौर पर HTTP requests (जैसे GET और POST) भेजने, URL parsing, और web resources को download करने के लिए उपयोग किया जाता है।

🔧 Installation (इंस्टॉलेशन)

urllib Python की standard library का हिस्सा है, इसलिए इसे अलग से इंस्टॉल करने की ज़रूरत नहीं होती।

✅ बस Python इंस्टॉल होना चाहिए।

python --version

यदि Python इंस्टॉल है, तो आप सीधे urllib का उपयोग कर सकते हैं।

📚 Main Modules of urllib

Module Name	Use (उपयोग)
`urllib.request`	URL से data भेजने और प्राप्त करने के लिए
`urllib.parse`	URL को parse (टुकड़े करना) और modify करने के लिए
`urllib.error`	errors handle करने के लिए
`urllib.robotparser`	robots.txt parser पढ़ने के लिए (web scraping में उपयोगी)

🧪 Basic Examples (बेसिक उदाहरण)

1. URL से Data डाउनलोड करना

from urllib.request import urlopen

url = "https://www.example.com"
response = urlopen(url)
html = response.read()

print(html.decode("utf-8"))

2. Query Parameters के साथ URL बनाना (GET Request)

from urllib.parse import urlencode
from urllib.request import urlopen

params = {'name': 'Himanshu', 'age': 25}
query_string = urlencode(params)

url = "https://httpbin.org/get?" + query_string
response = urlopen(url)
print(response.read().decode())

3. POST Request भेजना

from urllib import request, parse

data = parse.urlencode({'username': 'Himanshu', 'password': '1234'}).encode()
req = request.Request("https://httpbin.org/post", data=data, method="POST")

response = request.urlopen(req)
print(response.read().decode())

4. URL को Parse करना

from urllib.parse import urlparse

url = "https://www.example.com/page?name=Himanshu&age=25"
parsed = urlparse(url)

print(parsed.scheme)     # https
print(parsed.netloc)     # www.example.com
print(parsed.path)       # /page
print(parsed.query)      # name=Himanshu&age=25

💼 Real-world Project Examples (रियल प्रोजेक्ट उदाहरण)

📌 1. Web Scraper (वेब से डेटा खींचना)

उपयोग: News websites, job portals, या product data websites से डेटा खींचना।

from urllib.request import urlopen
from bs4 import BeautifulSoup  # Requires: pip install beautifulsoup4

url = "https://news.ycombinator.com"
html = urlopen(url).read()
soup = BeautifulSoup(html, 'html.parser')

for link in soup.find_all('a'):
    print(link.get('href'))

Results for "RequestException"

Making API Calls in Python