Python 3 preparation: make fallback SysCallError an actual exception class. The code defines a fallback version of SysCallError when import of OpenSSL.SSL. But in Python 3, defining it as None and then using in "except" statements results in: TypeError: catching classes that do not inherit from BaseException is not allowed

#!/usr/bin/env python
from __future__ import print_function
import zlib, base64, sys
print(base64.encodestring(zlib.compress(sys.stdin.read())))