It's really late now but I made a quick script which works for Windows, Mac and Linux, simply by using each command line:
import os, platform
def close():
if platform.system() == "Windows":
print("Press any key to exit . . .")
os.system("pause>nul")
exit()
elif platform.system() == "Linux":
os.system("read -n1 -r -p \"Press any key to exit . . .\" key")
exit()
elif platform.system() == "Darwin":
print("Press any key to exit . . .")
os.system("read -n 1 -s -p \"\"")
exit()
else:
exit()
It uses only inbuilt functions, and should work for all three (although I've only tested Windows and Linux...).