代码Python入门（四、条件语句）

#!/usr/bin/env python# -*- coding: UTF-8 -*-# Python程序语言指定任何非0和非空（null）值为true，0 或者 null为false 。a = 0b = 0if a == b:    print "a == b"    a = 1    b = 0else:    print "a != b"if a and b:    print "a and b is true"elif a or b:    print "a or b is true"elif not b and not a:    print "a = b = 0"else:    print "error"