Python 3.6 Requests SSLerror "unexpected eof while reading'

the following code works perfectly fine under Python 2.7:

import requests
url = "https://ec.europa.eu/clima/ets/"
r = requests.get(url)
r.status_code

However under Python 3.6 or 3.7 the code breaks with the error message:

SSLError: ("read error: Error([('SSL routines', 'ssl3_read_n', 'unexpected eof while reading')],)",)

Would be very thankful for every suggestion how to run it under Python 3.

P.S. requests version is 2.22 under all python versions

Update

It seems that the error was caused by openssl version 1.1.1e. Upgrading to 1.1.1f solved the problem for me.