如何将多个输入循环到字典文件 Wirth Python？

Question

My goal is to take two user inputs on a loop, save them in a dictionary, and when the user ends the loop, to have the save the dictionary.

# ------ Global Variables -------

user_cont = True

# ------- Functions -------

def get_Product():
    while user_cont:

        # get product code
        get_ProductCode()

        # get product number
        get_ProductNum()

        # save to dict
        create_ProductDict()

        # ask to continue
        user_continue()

        # save dict to file

def get_ProductCode(): works

def get_ProductNum(): works

def user_continue(): works but now is not getting prompted

What I'm currently trying to fix:

# save to dictionary
def create_ProductDict(): 
   product_Dict = {}
   productCode = get_ProductCode()
   productNum = get_ProductNum()
   print(product_Dict)

By my understanding on each loop, it should be receiving the returned productCode and productNum, and storing them? But now it won't ask the user to continue and end the loop so I can view the dictionary before I attempt to have the user save it.

In addition, I need to have the user choose a filename for the data.

As always, help is much appreciated!

Answer 1

There are two problems here. First issue is that your dictionary is being destroyed once the create_ProductDict() function ends, since the dictionary is created within the scope of the function.

One way to get around this would be to declare the dictionary in the global scope as a global variable. This way, the dictionary will persist as more items are added to it.

Next, your input variables currently aren't being used and the dictionary isn't being added to. The syntax for this is as follows:

productDict[productCode] = productNumber

So assuming that your input functions are equivalent to python's input() function, a solution that solves both of these issues would look something like this:

products = {}

def create_product_dict():
    code = input("Enter Code: ")
    num = input("Enter Number: ")
    products[code] = num 

create_product_dict()
create_product_dict()

print(products)

The output of this would be:

Enter Code: 123
Enter Number: 456
Enter Code: abc
Enter Number: 596
{'123': '456', 'abc': '596'}

Hope this is helpful:)

Answer 2

Try this:

def get_Product():
    user_cont = True
    while user_cont:
        get_ProductCode()
        get_ProductNum()
        create_ProductDict()
        user_cont = user_continue()

def user_continue():
    ip = input('Enter Yes to Continue: ').lower()
    return True if ip == 'yes' else False

Answer 3

Here is my finished main function after everything above pointed me in the direction I needed, but was not able to answer my questions entirely. My key finding was updating the dictionary before I asked to continue, and then adding the saving of the dictionary at the end. (The additional functions not included here as did not pertain to question/solution. Thank you!

    user_cont = True
    while user_cont:

        # get product code
        productCode = get_ProductCode()

        # get product number
        productNum = get_ProductNum()

        # print(productCode, productNum)

        # save to dict
        products[productCode] = productNum

        # debug to ensure dictionary was saving multi lines
        # print(products)

        # ask to continue
        user_cont = user_continue()

    for productCode, productNum in products.items():
        formproducts = (productCode + ", " + productNum)

        # print test
        # print(formproducts)

    # save dict to file
    FILENAME = input(str("Please enter a file name: "))
    file = open(FILENAME, "w")
    file.write( str(products) )
    file.close()
    print("File saved.")