Python USES the ctypes module to call the windowsapi to get the system version example

Python USES the ctypes module to call the Windows API GetVersionEx to get the current system version, without using python32

#!c:/python27/python.exe
#-*- coding:utf-8 -*-
" By calling the Window API Determine the current system version "
#  Demonstrated through ctypes call windows api function .
#  The author already knows python32 Can achieve the same function 
#  A semicolon at the end of a statement is a personal habit 
#  Make partial version judgment only, more detailed version judgment recommendation system OSVERSIONINFOEX The structure of the body 
import ctypes;
class OSINFO(ctypes.Structure):
    _fields_ = [
        ("dwOSVersionInfoSize",ctypes.c_long),
        ("dwMajorVersion",ctypes.c_long),
        ("dwMinorVersion",ctypes.c_long),
        ("dwBuildNumber",ctypes.c_long),
        ("dwPlatformId",ctypes.c_long),
        ("szCSDVersion",ctypes.c_char*128)
    ];
def GetSystemVersionString():
    kernel32 = ctypes.windll.LoadLibrary("kernel32.dll");
    os = OSINFO();
    os.dwOSVersionInfoSize = ctypes.sizeof(os);
    if kernel32.GetVersionExA(ctypes.byref(os))==0:
        return "Null Version";
    if os.dwPlatformId==1: #windows 95/98/me
        if os.dwMajorVersion==4 and os.dwMinorVersion==0:
            verStr = "windows 95";
        elif os.dwMajorVersion==4 and os.dwMinorVersion==10:
            verStr = "windows 98";
        elif os.dwMajorVersion==4 and os.dwMinorVersion==90:
            verStr = "windows me";
        else:
            verStr = "unknown version";
    elif os.dwPlatformId==2: #windows vista/server 2008/server 2003/xp/2000/nt
        if os.dwMajorVersion==4 and os.dwMinorVersion==0:
            verStr = "windows nt 4.0";
        elif os.dwMajorVersion==5 and os.dwMinorVersion==0:
            verStr = "windows 2000";
        elif os.dwMajorVersion==5 and os.dwMinorVersion==1:
            verStr = "windows xp";
        elif os.dwMajorVersion==5 and os.dwMinorVersion==2:
            verStr = "windows 2003";
        elif os.dwMajorVersion==6 and os.dwMinorVersion==0:
            verStr = "windows vista"; # or 2008
        elif os.dwMajorVersion>=0:
            verStr = "windows 7";
        else:
            verStr = "unknown version";
    else:
        return "unknown Version";
    return verStr+" build"+str(os.dwBuildNumber)+" "+ctypes.string_at(os.szCSDVersion);
if __name__ == "__main__":
    print(GetSystemVersionString());