Is Mechanize compliant with robots.txt rules?

Mechanize is a Python module for stateful programmatic web browsing. It is used to interact with websites and forms, click links, and submit forms, mimicking the behavior of a web browser.

The Python Mechanize library does not inherently obey robots.txt rules. robots.txt is a standard used by websites to communicate with web crawlers and other web robots about which areas of the site should not be processed or scanned.

Mechanize itself doesn't have built-in functionality to parse and obey the directives in a robots.txt file. However, you can manually handle robots.txt compliance in your code using additional libraries such as robotparser which is included in the Python standard library.

Here's a simple example of how to use robotparser in conjunction with Mechanize to respect robots.txt:

import mechanize
from urllib.robotparser import RobotFileParser

# URL of the site you want to scrape
url = "http://www.example.com"

# Create a RobotFileParser object and set its URL to the robots.txt file
rp = RobotFileParser()
rp.set_url(f"{url}/robots.txt")
rp.read()

# Check if the user agent (in this case, '*', meaning any user agent) can fetch the main page
user_agent = '*'
if rp.can_fetch(user_agent, url):
    # Initialize Mechanize Browser
    br = mechanize.Browser()

    # Open the URL
    br.open(url)
    # Now you can use Mechanize to navigate the site, as long as you stay within allowed paths

    # For example, to list all the links on the fetched page:
    for link in br.links():
        print(link)
else:
    print(f"Access to {url} has been disallowed by the robots.txt rules.")

It is important to note that obeying robots.txt is not enforced by law, but it is widely considered good etiquette to follow the rules specified in the file. Disregarding robots.txt can lead to your IP being banned from the site, legal actions from the site owners, and other potential ethical issues.

When writing a web scraper or crawler, always be respectful of the website's robots.txt rules, and consider the server load your bot might create. It's also a good practice to provide contact information in your bot's user agent string so that webmasters can reach out to you if necessary.