I've got an inexpensive certificate from EssentialSSL (Comodo is the CA) and I was surprised to discover that Python didn't recognize it.
requests.exceptions.SSLError: [Errno 1] _ssl.c:509: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
The certificate seems to be properly recognized by all major browsers, still Python does not validate it.
If possible I would prefer a simple install solution like the one of installing a package or a script.
I was a little bit surprised not to see Comodo in the default list of recognized CA certs, all major (5) browsers accept it but not Ubuntu wget/python/... (openssl i guess is the cause).