python-实现顺序栈

 7 class sqstack(object):      
  8     def __init__(self,maxsize):
  9         self.maxsize = maxsize
 10         self.stackElem = [] 
 11         self.top = 0        
 12                             
 13     def clear(self):        
 14         self.top = 0        
 15     def isEmpty(self):      
 16         return self.top == 0
 17     def length(self):       
 18         return self.top     
 19     def gettop(self):       
 20         if not self.isEmpty():
 21             return self.stackElem[self.top - 1]
 22         else:               
 23             return None     
 24     def push(self,item):    
 25         if self.top ==  self.maxsize:
 26             raise Exception("栈已满")
 27         else:               
 28             self.stackElem.append(item)
 29             self.top += 1   
 30     def pop(self):          
 31         if self.isEmpty():  
 32             return None     
 33         else:               
 34             self.top -= 1   
 35             values =  self.stackElem[self.top]
 36             del self.stackElem[self.top]
 37             return values   
 38     def display(self):      
 39         for i in self.stackElem:
40             print(i,end = " ")
 41         print()   
 42                   
 43 if __name__ == "__main__": 
 44     sqstack1 = sqstack(5)  
 45     sqstack1.push(1)       
 46     sqstack1.push(2)       
 47     sqstack1.push(3)       
 48     sqstack1.push(4)       
 49     sqstack1.push(5)
 50     print(sqstack1.gettop())                                       
 51     sqstack1.display()
 52     print(sqstack1.length())
 53     print(sqstack1.pop())
 54     sqstack1.display()

运行结果：

5
1 2 3 4 5
5
5
1 2 3