Installing dependencies
-----------------------
Make sure you have Python 3.7+ somewhere.

Option 1: Using pipenv

    pip3 install pipenv  # skip if pipenv is already installed
    cd <project-dir>
    pipenv install --python <path-to-python-binary>  # --python is optional
    pipenv shell  # start shell

Option 2: Using venv

    cd <project-dir>
    python -m venv ./venv
    source venv/bin/activate
    pip install -r requirements.txt


Running the crawler
-------------------
Show help

    ./main.py -h

Crawl URL with concurrency=10 and depth=2

    ./main.py -n 10 -d 2 -o output.json https://old.reddit.com

Check output

    less output.json


Features
--------
- Configurable concurrency and depth limit.
- Uses asyncio for faster performance and reduced CPU usage.
- Uses url-normalize for normalizing URLs to prevent duplicates.

Limitations
-----------
- Very basic output format
- Does not handle all kinds of URLs in <a> tags
- Only handles responses with status 200 and text/html content type
- Hardcoded breadth-first crawling, no option to change
- aiohttp can fail randomly (SSL certificate issues)