Python 列表/字典不保留用户输入

Question

#PART 1

Customers=[]
Customer_name=input("Please enter your name: ") #User name Input
Customers.append(Customer_name)
Mem_Customers=[]
items={"Shirt":100, "Trouser":150, "Shorts":50, "Tshirt":100}  
Products=["Shirt","Trouser","Shorts","Tshirt"] 
Price=[100,150,50,100]

def menu():
print(" Welcome to RMIT Retail Management System")
print()
print("#"*40)
print()
print("Please choose form the following options")
print("1: Place an order")
print("2: Add/Update Products and Prices")
print("3: Display existing Customers")
print("4: Display existing Customers with Membership")  
print("5: Display existing Products")  
print("0: Exit the menu" ) 
print()  
print("#"*40)
menu()
option=input(" Choose one Option:")

while int(option)!=0:
if int(option)==1:
Choose_Product=input("Please enter the product you want to choose (valid product only i.e Shirt,Trouser,Shorts,Tshirt) : ")

        while not Choose_Product in items:
            print("Please enter a valid product")
            Choose_Product=input("Please enter the product you want to choose (valid product only i.e Shirt,Trouser,Shorts,Tshirt) : ")
        
        
        valid_quantity= False
        while not valid_quantity:
            Quantity=input("Please enter the quantity of the products required(Positive integer only): ") 
            if Quantity.strip().isdigit() and int(Quantity)>0:
                valid_quantity= True
            else:
                print("Please enter a valid integer")
    
        
        
        response=False
        while not response:  
            Membership=input("Please specify that you want a membership or not Y/N : ") 
            if Membership  in "Y" "N":
                response=True
            else:
                print("Please enter a valid response")
    
        
    
    
    
    # Membership
        if Membership=="Y" and Choose_Product=="Shirt":
            Mem_Customers.append(Customer_name)
            print(Customer_name  +"purchases"+str(Quantity)+ "x"+ Choose_Product)
            print("Unit price :      100 AUD")
            print(Customer_name+"Gets a discount of 5%")
            totalprice=(items["Shirt"]*int(Quantity))
            finalprice=totalprice-(totalprice*0.05)
            print("Total price : "+str(finalprice))
    
        if Membership=="Y" and Choose_Product=="Trouser":
            Mem_Customers.append(Customer_name)
            print(Customer_name +"purchases"+str(Quantity)+ "x"+ Choose_Product)
            print("Unit price :      150 AUD")
            print(Customer_name+"Gets a discount of 5%")
            totalprice=(items["Trouser"]*int(Quantity))
            finalprice=totalprice-(totalprice*0.05)
            print("Total price : "+str(finalprice))
    
        if Membership=="Y" and Choose_Product=="Shorts":
                Mem_Customers.append(Customer_name)
                print(Customer_name +"purchases"+str(Quantity)+ "x"+ Choose_Product)
                print("Unit price :      50 AUD")
                print(Customer_name+"Gets a discount of 5%")
                totalprice=(items["Shorts"]*int(Quantity))
                finalprice=totalprice-(totalprice*0.05)
                print("Total price : "+str(finalprice))
    
        if Membership=="Y" and Choose_Product=="Tshirt":
                Mem_Customers.append(Customer_name)
                print(Customer_name +"purchases"+str(Quantity)+ "x"+ Choose_Product)
                print("Unit price :      100 AUD")
                print(Customer_name+"Gets a discount of 5%")
                totalprice=(items["Tshirt"]*int(Quantity))
                finalprice=totalprice-(totalprice*0.05)
                print("Total price : "+str(finalprice))
    
        # No Membership
    
        if Membership=="N" and Choose_Product=="Shirt":             
                print(Customer_name +"purchases"+str(Quantity)+ "x"+ Choose_Product)
                print("Unit price :      100 AUD")
                totalprice=(items["Shirt"]*int(Quantity))
                finalprice=totalprice
                print("Total price : "+str(finalprice))
    
        if Membership=="N" and Choose_Product=="Trouser":
                print(Customer_name +"purchases"+str(Quantity)+ "x"+ Choose_Product)
                print("Unit price :      150 AUD")
                totalprice=(items["Trouser"]*int(Quantity))
                finalprice=totalprice
                print("Total price : "+str(finalprice))
    
        if Membership=="N" and Choose_Product=="Shorts":
                print(Customer_name +"purchases"+str(Quantity)+ "x"+ Choose_Product)
                print("Unit price :      50 AUD")
        
                totalprice=(items["Shorts"]*int(Quantity))
                finalprice=totalprice
                print("Total price : "+str(finalprice))
    
        if Membership=="N" and Choose_Product=="Tshirt":
                print(Customer_name +"purchases"+str(Quantity)+ "x"+ Choose_Product)
                print("Unit price :      100 AUD")
                totalprice=(items["Tshirt"]*int(Quantity))
                finalprice=totalprice
                print("Total price : "+str(finalprice))  
               
    
    
    
    if int(option)==2: 
        add_product=input("Please enter the new products separated by , :").split(",")
        Products.append(add_product)
        add_price=input("Please enter the price of the products separated by , :").split(",")
        Price.append(add_price)
        for i in range(len(add_product)):
            add_product[i]=add_product[i]
            add_price[i]=add_price[i]
    
            if add_product[i] in items:
                print("The product already exists and prices will be updated")
                items[add_product[i]]=add_price[i]
            else:
                print("New product has been entered and will be updated ")
                items[add_product[i]]=add_price[i]
            
    if int(option)==3:
        print()
        print("The existing customers are:""\n")
        print(list(set(Customers)))
        break
    if int(option)==4:
        print()
        print("The customers with membership are:""\n")
        print(list(set(Mem_Customers)))
        break
    if int(option)==5:
        print()
        print("The existing products are:""\n")
        print(list(set(Products)))
        break

if int(option)==0:
print()
print("Thanks for using our program bye..""\n")

menu()

My above program is not able to store the user input for add/update new programs. It shows at the runtime the new added items but when I run the program again it shows the default values. Also I want to change the part where I am doing calculations of products ( Under the #Membership comment). As I have only used the default values there But in the case the user adds new items I want to be able to calculate that part also. I am having trouble in figuring out that part.

I am a beginner at programming, so any help or suggestions much appreciated.

Also, for this Assignment our instructor has restricted us to use any modules.

Answer 1

you have something wrong in this code,but don`t worry about that

first of all,

 if Membership == "Y" and Choose_Product == "Trouser": Mem_Customers.append(Customer_name) print(Customer_name + "purchases" + str(Quantity) + "x" + Choose_Product) print("Unit price: 150 AUD") print(Customer_name+"Gets a discount of 5%") totalprice = (items["Trouser"]*int(Quantity)) finalprice = totalprice-(totalprice*0.05) print("Total price: "+str(finalprice))

all the items["shirt"], items[Tshirt], items[Trouser]

you can use items[Choose_Product] in your program like this

if Membership == "Y":

​        Mem_Customers.append(Customer_name)

​        print()

​        print(Customer_name+":"+"purchases :"+str(Quantity) + " x " + Choose_Product)

​        print("Unit price :   "+str(items[Choose_Product])+" AUD")

​        print(Customer_name+"Gets a discount of 5%")

​        totalprice = (items[Choose_Product]*int(Quantity))

​        finalprice = totalprice-((totalprice)*0.05)

​        print("Total price : "+str(finalprice))

when you want add/update new items you don`t need add anything

secondly,I think you should add menu information in the while loop

when user finish a operate,he/she can do others

finally,when people,input price,we should change str to int or float

if you don`t do this

TypeError: can't multiply sequence by non-int of type 'xxx'

sorry,English is not my native language,and I hope this answer can help you

I write a new file based on your code, maybe it can help you understand in few minutescode gist

BTW,don`t copy code to your instructor. lol. you need understand it

have a good day.