urlparse does not raise exception for an invalid url

Question

I have the following code, which is supposed to check if an entered url is valid:

#!/usr/bin/env python3

import sys
import urllib.parse

# ...

def checkValidURL(someURL):
    try:
        parsed_url = urllib.parse.urlparse(someURL)
        isURL = True
    except ValueError:
        print("Invalid URL!")
        sys.exit(0)

# ...

if __name__ == "__main__":
    checkValidURL(someURL)

If an invalid URL is entered, for example: someURL="http://ijfjiör@@@a:43244434::" it should raise a ValueError as described here:

Characters in the netloc attribute that decompose under NFKC normalization (as used by the IDNA encoding) into any of /, ?, #, @, or : will raise a ValueError. If the URL is decomposed before parsing, no error will be raised.

However, no exception is raised and the URL seems to be valid.

Is there anything I am doing wrong or is there any other way to check the validity of an URL?

Answer 1

Your URL doesn't decompose into a string which contains a prohibited character, so the quotation is not at all relevant here.

The language in the quote is strictly about disallowing the use of internationalized domain name encoding like http://xn--foo/ to produce something like http://?/ and since you are not doing that here, no ValueError is generated or indeed to be expected.

(Sorry, not in a place where I can create a genuine working example.)