when scraping amazon there is an exception

[sohailoo]

these re the links i'm trying to scrape

---
refresh_interval: 2 # seconds
urls:
  - 
  - https://www.amazon.com/ASUS-Graphics-DisplayPort-Military-Grade-Certification/dp/B08HH5WF97
  - https://www.amazon.com/GeForce-Gaming-Graphics-Technology-Backplate/dp/B08NWBG14N
  - https://www.amazon.com/MSI-GeForce-RTX-3080-10G/dp/B08HR7SV3M
  - https://www.amazon.com/ASUS-Graphics-DisplayPort-Axial-tech-2-9-Slot/dp/B08J6F174Z
...

D2020-12-03 02:21:49,882 using parser: html.parser
D2020-12-03 02:21:49,884 registering custom scraper for domain: amazon
D2020-12-03 02:21:49,890 registering custom scraper for domain: bestbuy
D2020-12-03 02:21:49,896 registering custom scraper for domain: bhphotovideo
D2020-12-03 02:21:49,902 registering custom scraper for domain: microcenter
D2020-12-03 02:21:49,910 registering custom scraper for domain: newegg
E2020-12-03 02:21:50,006 caught exception
Traceback (most recent call last):
  File "/src/run.py", line 41, in main
    config = parse_config(args.config)
  File "/src/config.py", line 37, in parse_config
    return Config(refresh_interval, max_price, data['urls'])
  File "/src/config.py", line 23, in __init__
    self.urls = [URL(url) for url in sorted(set(urls))]
TypeError: '<' not supported between instances of 'NoneType' and 'str'

[EricJMarti]

The line that follows urls: is a blank entry. I would delete this line and try again.