Python Cookies and http.cookiejar Module

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No, not the delicious chocolate chip kind (although those are pretty great too). We’re talking about HTTP cookies, which are small text files stored on your computer by websites you visit.

Now, if you’ve ever wondered how a website remembers that you’re logged in or has items in your cart, it’s because of these little guys! And guess what? Python makes working with them super easy thanks to the `http.cookiejar` module.

Before anything else let’s create a new Python file and import the necessary modules:

import requests
from bs4 import BeautifulSoup
import re
import time
import os
from http.cookiejar import CookieJar, LWPCookieJar

# Set up our cookie jar to store cookies for later use
cj = CookieJar()
opener = requests.Session()
opener.cookies = cj

We’re using `requests`, `BeautifulSoup`, and `time` modules as usual, but we’ve also added the `http.cookiejar` module to handle cookies. We create a new cookie jar object called `cj` and set it up for use with our session (which is created by calling `Session()` on the `requests` library).

Now let’s say you want to log in to your favorite website using Python. Here’s an example of how we can do that:

# Set up login credentials and URL for login page
username = "your_username"
password = "your_password"
login_url = "https://www.example.com/login/"

# Navigate to the login page using our session object
opener.get(login_url)

# Parse HTML content and find input fields for username and password
soup = BeautifulSoup(opener.content, 'html.parser')
username_input = soup.find("input", {"name": "username"})
password_input = soup.find("input", {"name": "password"})

# Fill in input fields with our credentials and submit the form using requests library
username_input["value"] = username
password_input["value"] = password
login_form = soup.find('form', {'action': '/login'})
data = dict(list(login_form['enctype'] == 'multipart/form-data') + list(login_form[1]['name'] for login_form in login_form['elements']))
for key, value in data.items():
    if isinstance(value, (list, tuple)):
        for v in value:
            opener.post(login_url, data=data)
            time.sleep(1) # Wait 1 second before proceeding to next step
            soup = BeautifulSoup(opener.content, 'html.parser')
            if "Welcome" in str(soup):
                print("Logged in successfully!") break
    else:
        opener.post(login_url, data=data)
        time.sleep(1) # Wait 1 second before proceeding to next step
        soup = BeautifulSoup(opener.content, 'html.parser')
        if "Welcome" in str(soup):
            print("Logged in successfully!") break

In this example, we’re using the `requests` library to navigate to our login page and fill out the input fields with our credentials. We then submit the form using a POST request (which is necessary for sending data to the server).

But wait what about those ***** cookies? How do we make sure they’re stored properly so that we don’t have to log in every time we visit our favorite website? That’s where `http.cookiejar` comes in! By setting up a cookie jar object and using it with our session, any cookies received during the login process will be automatically saved for future use:

# Set up login credentials and URL for login page
username = "your_username"
password = "your_password"
login_url = "https://www.example.com/login/"

# Navigate to the login page using our session object
opener.get(login_url)

# Parse HTML content and find input fields for username and password
soup = BeautifulSoup(opener.content, 'html.parser')
username_input = soup.find("input", {"name": "username"})
password_input = soup.find("input", {"name": "password"})

# Fill in input fields with our credentials and submit the form using requests library
username_input["value"] = username
password_input["value"] = password
login_form = soup.find('form', {'action': '/login'})
data = dict(list(login_form['enctype'] == 'multipart/form-data') + list(login_form[1]['name'] for login_form in login_form['elements']))
for key, value in data.items():
    if isinstance(value, (list, tuple)):
        for v in value:
            opener.post(login_url, data=data)
            time.sleep(1) # Wait 1 second before proceeding to next step
            soup = BeautifulSoup(opener.content, 'html.parser')
            if "Welcome" in str(soup):
                print("Logged in successfully!") break
    else:
        opener.post(login_url, data=data)
        time.sleep(1) # Wait 1 second before proceeding to next step
        soup = BeautifulSoup(opener.content, 'html.parser')
        if "Welcome" in str(soup):
            print("Logged in successfully!") break

Now that we’re logged in, any cookies received during this session will be automatically saved for future use by our `http.cookiejar`. This means that when you visit the same website again later on (without logging out), your credentials and other preferences will still be remembered thanks to those little text files stored on your computer!

And there you have it a quick tutorial on how to use Python’s `http.cookiejar` module for working with HTTP cookies.

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