检测系统版本、python发行版本

import sys

is_jython = sys.platform.startswith(\'java\')
is_pypy = hasattr(sys, \'pypy_version_info\')
is_win = (sys.platform == \'win32\')
is_cygwin = (sys.platform == \'cygwin\')
is_darwin = (sys.platform == \'darwin\')