如何在Python中將NoneType轉換爲int？

Question

我想嘗試在Python中使用堆棧將十進制數轉換爲二進制數，但是出現此錯誤。

class Stack: 
    def __init__(self): 
     self.items = [] 

    def is_empty(self): 
     return self.items == [] 

    def push(self, item): 
     self.items.append(item) 

    def pop(self): 
     self.items.pop() 

    def peek(self): 
     return self.items[len(self.items)-1] 

    def size(self): 
     return len(self.items) 



def divideBy2(decNumber): 
    remstack = Stack() 

    while decNumber > 0: 
     rem = decNumber % 2 
     remstack.push(rem) 
     decNumber = decNumber // 2 

    binString = "" 
    while not remstack.is_empty(): 
     binString = binString + str(remstack.pop()) 

    return binString 

print(divideBy2(42)) 

Answer 1

您的pop方法缺少return。