基本上，我正在制作一个应用程序，以更好地帮助我管理自己的eBay商店。我对编程和OOP还是很陌生。看了一些教程之后，我整理了以下代码。到目前为止，一切工作正常。我目前坚持的是，当用户输入要库存的物料时，它没有保存。而且，当用户想要查看库存时，他们添加的项目将不会填充。任何意见或建议都将是徒劳的。
def Inventory():
All_Inventory = {}
class Ebay_Inventory:
def __init__(self, manufacturer, object_type, price):
self.manufacturer = manufacturer
self.object_type = object_type
self.price = price
def add_item(self):
manufacturer = input("Enter Manufacturer: ")
object_type = input("Enter what the item is: ")
price = input("Enter price: ")
item_info = Ebay_Inventory(manufacturer, object_type, price)
All_Inventory = item_info
print("Item added successfully")
def delete_item(self):
delete = input("What is the item you want to delete?: ")
if delete in All_Inventory.keys():
del[delete]
print("The item entered has been deleted.")
else:
print("Item not found")
def sale_status(self):
update = input("What is the item you want to update?:")
if update in All_Inventory.keys():
pass
else:
print("Item not found")
user=True
while user:
print("\n1. Add to item inventory")
print("2. Remove item from inventory")
print("3. Update sale status")
print("4. View inventory")
print("5. Exit program")
user_wants=input("What would you like to do today?")
if user_wants=="1":
Ebay_Inventory.add_item(input)
elif user_wants=="2":
Ebay_Inventory.delete_item(input)
elif user_wants=="3":
Ebay_Inventory.sale_status(input)
elif user_wants=="4":
print(All_Inventory)
elif user_wants=="5":
print("\n Thank you for using item inventory.")
break
elif user_wants!="":
print("\n Input not understood. Please try again.")
答案 0 :(得分：0)
您需要阅读有关范围，OOP和字典的信息：
您没有添加到Inventory.All_Inventory中-您使用All_Inventory = item_info创建了新的本地
您将静态类属性和实例属性混合在一起，请阅读：
您错误地删除/访问字典-请参阅：
已修复：
class Ebay_Inventory:
Inventory = {} # class property
@staticmethod
def print_inventory():
for k in Ebay_Inventory.Inventory:
for i in Ebay_Inventory.Inventory[k]:
print(k,i)
class Ebay_Item:
def __init__(self, key, manufacturer, object_type, price):
self.manufacturer = manufacturer
self.object_type = object_type
self.price = price
self.key = key
def __str__(self):
return f"{self.manufacturer} {self.object_type} {self.price}"
def __repr__(self):
return str(self)
@staticmethod
def add_item(key=None, man=None, obj=None, pri=None):
# use values if given, else ask - this is for demo purposes only
key = key or input("Enter key: ")
manufacturer = man or input("Enter Manufacturer: ")
object_type = obj or input("Enter what the item is: ")
price = pri or input("Enter price: ")
# create new item
item_info = Ebay_Inventory.Ebay_Item(key, manufacturer, object_type, price)
# add to class member, create key if need be
Ebay_Inventory.Inventory.setdefault(item_info.key,[]).append(item_info)
def delete_item(key=None):
delete = key or input("What is the item you want to delete?: ")
if delete in Ebay_Inventory.Inventory:
del Ebay_Inventory.Inventory[delete]
print("The item entered has been deleted.")
else:
print("Item not found")
def __str__(self):
return Ebay_Inventory.print_inventory()
# add 2 items and print
Ebay_Inventory.add_item(1,"Me","Me",1000)
Ebay_Inventory.add_item(2,"You","You",1000)
Ebay_Inventory.print_inventory()
# remove non existent and existent item and print
Ebay_Inventory.delete_item(3)
Ebay_Inventory.delete_item(2)
Ebay_Inventory.print_inventory()
输出：
1 Me Me 1000
2 You You 1000
Item not found
The item entered has been deleted.
1 Me Me 1000
答案 1 :(得分：0)
很抱歉，您需要对代码进行大量修改，但是我认为这更像您要使用的代码：
class EbayInventory:
def __init__(self):
self.all_inventory = []
def print_items(self):
print('Current item list by index:')
for i in range(0, len(self.all_inventory)):
print("{} -> {}".format(i+1, self.all_inventory[i]))
def add_item(self):
manufacturer = input("Enter Manufacturer: ")
object_type = input("Enter what the item is: ")
price = input("Enter price: ")
item = {'manufacturer': manufacturer, 'type': object_type, 'price': price}
self.all_inventory.append(item)
print("Item added successfully")
def delete_item(self):
self.print_items()
delete = int(input("Item id you want to delete: "))
try:
del self.all_inventory[delete - 1]
print("The item entered has been deleted.")
except Exception as e:
print("An error occurred deleting that item, details below")
print(e)
def sale_status(self):
self.print_items()
update_index = int(input("Item id you want to update: "))
if update_index > len(self.all_inventory) or update_index <= 0:
print("You're trying to change an item that doesn't exist!!")
return
print("OK. Let's get that item up to date!")
manufacturer = input("Enter Manufacturer: ")
object_type = input("Enter what the item is: ")
price = input("Enter price: ")
item = {'manufacturer': manufacturer, 'type': object_type, 'price': price}
self.all_inventory[update_index - 1] = item
print("OK. We got that update taken care of")
if __name__ == "__main__":
my_app = EbayInventory()
while True:
print("\n1. Add to item inventory")
print("2. Remove item from inventory")
print("3. Update sale status")
print("4. View inventory")
print("5. Exit program")
user_wants = input("Please enter the number corresponding to how you would like help: ")
if user_wants == "1":
my_app.add_item()
elif user_wants == "2":
my_app.delete_item()
elif user_wants == "3":
my_app.sale_status()
elif user_wants == "4":
my_app.print_items()
elif user_wants == "5":
print("Thank you for using item inventory.")
break
else:
print("Input not understood. Please try again.")
您有一个变量user，它没有任何作用。您可以简单地使用while True:输入无限循环。如果您想按自己的方式循环，那么可以用break代替循环user = False来代替循环。有时这是一个很巧妙的技巧，但我认为在这里没有意义。在我看来，清单确实是唯一可以通过存储在您的类中而受益的东西，然后这些方法可以通过self.all_inventory对其进行访问以对其进行调整。我将您的代码移到了add_item()和sale_status()方法中，要求输入项目，因此现在主要的代码块看起来更加整洁。我还将其包装在if __name__ == "__main__":中，以便您可以将此类导入另一个项目，而无需运行整个程序！我还使用try:和except:子句进行了一些基本的错误检查。我认为您误解了Class和Instance之间的区别。因此，在我的代码中，Class是EbayInventory，而Instance是my_app。您可以像使用my_app = EbayInventory()一样创建类的实例，然后自身现在引用my_app。通过这种方式，我可以打电话给my_app.add_item()。但是，您可以有多个对象实例，并且它们在计算机内存中都有各自的空间。所以你可能会说：
app1 = EbayInventory()
app2 = EbayInventory()
app1.add_item()
并且只有app1将具有任何项目，而app2仍然是一个空列表，但仍具有methods可以通过app2.add_item()建立库存。但是，要回答您的主要问题，请不要调用函数Inventory()，因此不存在用于保存信息的函数。实际上，当您调用item_info = Ebay_Inventory(manufacturer, object_type, price)时，您是在创建类的实例，在这里这样做实在是没有意义的，因为这意味着在下一行您可以说item_info.add_item()，而这会成为另一个实例，但您并未将这些信息保存在任何地方，因此您将永远无法获取它！