Python|维护杂货清单
问题陈述 ：
制作超市购物的杂货清单，包括名称、价格和数量；如果列表已经包含一个项目，那么只更新价格和数量它不应该再次附加项目名称。最初询问用户他/她的预算
并在列表中添加新项目后减去预算。如果预算为零/0，则无法购买更多商品，并且如果剩下一些钱并且用户添加的商品大于剩余预算，则通知“价格过高”或任何其他消息。制作清单后，预算中剩余的任何资金都应显示出清单中预算内的项目。
验证是必须的。
例子：
User GO with following question
Enter Your budget : 500
1.Add an item
2.Exit
Enter your choice : 1
Enter product : corn flour
Enter quantity : 1.5 kg
Enter Price : 100
Amount left : 400
1.Add an item
2.Exit
Enter your choice : 1
Enter product : wheat
Enter quantity : 2 kg
Enter Price : 100
Amount left : 300
1.Add an item
2.Exit
Enter your choice : 1
Enter product : corn flour
Enter quantity : 2 kg
Enter Price : 250
Amount left : 150
1.Add an item
2.Exit
Enter your choice : 1
Enter product : rice
Enter quantity : 5 kg
Enter Price : 300
Can't Buy the product ###(because budget left is 150)
1.Add an item
2.Exit
Enter your choice : 1
Enter product : xyz
Enter quantity : 1 kg
Enter Price : 50
Amount left : 100
1.Add an item
2.Exit
Enter your choice : 2
Amount left can buy you wheat
GROCERY LIST is:
Product name Quantity Price
corn flour 2 kg 250
wheat 2 kg 100
xyz 1 kg 50尝试理解上面的问题陈述和输出解释并在去解决方案之前自己尝试
代码：检查杂货清单的Python代码
Python3
# This loop will go on until the budget is integer or float
while True:
try:
bg = float(input("Enter your budget : "))
# if budget is integer or float it will be stored
# temporarily in variable 's'
s = bg
except ValueError:
print("PRINT NUMBER AS A AMOUNT")
continue
else:
break
# dictionary to store product("name"), quantity("quant"),
# price("price") with empty list as their values
a ={"name":[], "quant":[], "price":[]}
# converting dictionary to list for further updation
b = list(a.values())
# variable na value of "name" from dictionary 'a'
na = b[0]
# variable qu value of "quant" from dictionary 'a'
qu = b[1]
# variable pr value of "price" from dictionary 'a'
pr = b[2]
# This loop terminates when user select 2.EXIT option when asked
# in try it will ask user for an option as an integer (1 or 2)
# if correct then proceed else continue asking options
while True:
try:
ch = int(input("1.ADD\n2.EXIT\nEnter your choice : "))
except ValueError:
print("\nERROR: Choose only digits from the given option")
continue
else:
# check the budget is greater than zero and option selected
# by user is 1 i.e. to add an item
if ch == 1 and s>0:
# input products name
pn = input("Enter product name : ")
# input quantity of product
q = input("Enter quantity : ")
# input price of the product
p = float(input("Enter price of the product : "))
if p>s:
# checks if price is less than budget
print("\nCAN, T BUT THE PRODUCT")
continue
else:
# checks if product name already in list
if pn in na:
# find the index of that product
ind = na.index(pn)
# remove quantity from "quant" index of the product
qu.remove(qu[ind])
# remove price from "price" index of the product
pr.remove(pr[ind])
# insert new value given by user earlier
qu.insert(ind, q)
# insert new value given by user earlier
pr.insert(ind, p)
# subtracting the price from the budget and assign
# it to 's' sum(pr) is because pr = [100, 200] if
# budget is 500 then s = bg-sum(pr) = 200
# after updating for same product at index 0 let
# pr = [200, 200] so s = 100
s = bg-sum(pr)
print("\namount left", s)
else:
# append value of in "name", "quantity", "price"
na.append(pn)
# as na = b[0] it will append all the value in the
# list eg: "name":["rice"]
qu.append(q)
# same for quantity and price
pr.append(p)
# after appending new value the sum in price
# as to be calculated
s = bg-sum(pr)
print("\namount left", s)
# if budget goes zero print "NO BUDGET"
elif s<= 0:
print("\nNO BUDGET")
else:
break
# will print amount left in variable 's'
print("\nAmount left : Rs.", s)
# if the amount left equals to any amount in price list
if s in pr:
# then printing the name of the product which can buy
print("\nAmount left can buy you a", na[pr.index(s)])
print("\n\n\nGROCERY LIST")
# print final grocery list
for i in range(len(na)):
print(na[i], qu[i], pr[i])