Pip install via local proxy server behind secured firewall

Just found that PIP install works so well at home but not in office. One of the restriction is the firewall security to prevent non-http traffic passing through during package installation. Here's a trick:

Changing from this:

$
$ pip install --upgrade git+git://github.com/XXXXX/YYYYY.git

to this:

$ # x.y.z.s is IP address
$ # port is port number
$ pip --proxy=x.y.z.s:port install --upgrade git+https://github.com/XXXXX/YYYYY.git

Most firewall won't block http/https traffic which is supposed to be categorized as web traffic.