How do I disable the ssl check in python 3.x?

Use urllib.request.urlopen with custom ssl context:

import ssl
import urllib.request

ctx = ssl.create_default_context()
ctx.check_hostname = False
ctx.verify_mode = ssl.CERT_NONE

with urllib.request.urlopen(url_string, context=ctx) as u, \
        open(file_name, 'wb') as f:
    f.write(u.read())

Alternatively, if you use requests library, it could be simpler:

import requests

with open(file_name, 'wb') as f:
    resp = requests.get(url_string, verify=False)
    f.write(resp.content)

Function urllib.request.urlretrieve doesn't accept any SSL options but urllib.request.urlopen does.

However instead creating a secure SSL context with ssl.create_default_context() and making it insecure you can create an insecure context with ssl.SSLContext():

This:

ctx = ssl.create_default_context()
ctx.check_hostname = False
ctx.verify_mode = ssl.CERT_NONE

is equivalent to:

ctx = ssl.SSLContext()

(For Python < 3.5.3 use ssl.SSLContext(ssl.PROTOCOL_TLSv1))

Which makes a nice one-liner:

import ssl
import urllib.request

with urllib.request.urlopen("https://wrong.host.badssl.com/", context=ssl.SSLContext()) as url:
    print(url.read())