#!/usr/bin/env python # -*- coding:utf-8 -*- class Stack(object): """docstring for Stack""" def __init__(self, cap): super(Stack, self).__init__() self.__cap = cap # 栈大小 self.__length = 0 # 栈长度 if self.__cap < 0: raise ValueError("length of Stack can not be negtive") self.__values = [0 for x in xrange(0, self.__cap)] def empty(self): return self.__length is 0 def push(self, x): if self.__length >= self.__cap: raise IndexError("stack is full, can not push any object") self.__values[self.__length] = x self.__length += 1 def pop(self): if self.__length <= 0: return None self.__length -= 1 return self.__values[self.__length] def __str__(self): return "".join(["Stack, Value: ", str(self.__values), " cap: ", str(self.__cap), " length:", str(self.__length)]) def main(): stack = Stack(5) for x in xrange(0, 5): stack.push(x) print "full stack" print stack print "pop everything" for x in xrange(0, 7): print stack.pop() print "index of bound error" for x in xrange(0, 7): stack.push(x) if __name__ == '__main__': main()