输入语句只是在循环中继续运行

Question

嗨，我是albert，我正在学习python，在我写的这段代码中，我打算打印总数，但是输入语句只是继续循环

print("this program prints your invoice")
while True:
ID = input("item identification: ")
if ID == "done":
break
if len(ID) < 3:
print("identification must be at least 3 characters long")
exit(1)
break
try:
Quantity = int(input("quantity sold: "))
except ValueError:
print("please enter an integer for quantity sold!!!")
exit(2)
if Quantity <= 0:
break 
print("please enter an integer for quantity sold!!!")
exit(3)
try:
price = float(input("price of item"))
except ValueError:
print("please enter a float for price of item!!")
exit(4)
if price <= 0:
print("please enter a positive value for the price!!!")
exit(5)
break
cost = 0
total = cost + (Quantity*price)
print(total)

Answer 1

我想你需要这个

cost = 0
total = cost + (Quantity*price)
print(total)

在内while循环。否则，完全跳过循环。

Answer 2

试试这个:

print("This program prints your invoice")
total = 0
more_to_add = True
while more_to_add == True:
ID = input("Item identification: ")
if len(ID) < 3:
print("Identification must be at least 3 characters long")
continue
try:
Quantity = int(input("Quantity sold: "))
except ValueError:
print("Please enter an integer for quantity sold!!!")
continue
if Quantity <= 0:
print("Please enter an integer for quantity sold!!!")
continue
try:
price = float(input("Price of item: "))
except ValueError:
print("Please enter a float for price of item!!")
continue
if price <= 0:
print("Please enter a positive value for the price!!!")
continue
total = total + (Quantity*price)
answer = input("Want to add more? (Y/N)" )
if answer == 'Y':
more_to_add = True
else:
more_to_add = False
print(total)