How to fix dictionary not counting duplicate numbers as new entries-CodePudding

Currently, my code is as follows:

max_length = 3

squares = {}

while len(squares) < max_length:
    print("Enter the side length of the square:")
    side = input()
    side = int(side)
    Perimeter = side*4
    Area = side*side

    squares[Area] = Perimeter

And the problem with this is that when you enter the same side length multiple times, it does not count it as a new entry, and instead keeps asking until unique side lengths are entered. Why is this and how can I fix it? If this is not possible with dictionaries, is there any alternative ways of doing this so it does allow duplicate keys and then can be converted to a DataFrame for plotting?

CodePudding user response：

You're going to have to make a counter in the while loop that tracks how many inputs the user gives. Dictionaries don't allow for duplicate entries, so every time you reference a key that is already in the dictionary, you will just overwrite the current value.

ex.

dictionary = {}
dictionary['key1'] = 'value1'
dictionary['key2'] = 'value2'
print(dictionary.items())  
>> dict_items([('key1', 'value1'), ('key2', 'value2')])

now, given the same dictionary, we are going to call the same key: dictionary = {}

dictionary['key1'] = 'value1'
dictionary['key2'] = 'value2'
dictionary['key1'] = 'value3'
print(dictionary.items())  
>> dict_items([('key1', 'value3'), ('key2', 'value2')])

So, as you can see you are just overwriting the value that corresponds to the key. If you want to have your loop stop after 3 inputs, just do something like this:

max_length = 3

squares = {}
number_of_inputs = 0
while number_of_inputs < max_length:
    print("Enter the side length of the square:")
    side = int(input(...))
    
    Perimeter = side*4
    Area = side*side

    squares[Area] = Perimeter
    number_of_inputs  = 1

Otherwise, you are going to need to check if the key already exists and handle the situation from there - not sure your end goal so cant help with that.

CodePudding user response：

This happen because in dictionary it's doesn't allow duplicates keys key should be unique and have one value.

To solve this

max_length = 3

    squares = {}

    while len(squares) < max_length:
        side = input("Enter the side length of the square:")
        side = int(side)
        Perimeter = side * 4
        Area = side * side
        if Area in squares.keys():
            print(f"this is side already exist {side} chose differ one")
        else:
            squares[Area] = Perimeter

CodePudding user response：

I have solved it by using a list instead and then using list.append to add new values. Like so

max_length = 3
inputs = 0
squares = []

while inputs < max_length:
    print("Enter the side length of the square:")
    side = input()
    side = int(side)
    Perimeter = side*4
    Area = side*side
    inputs = inputs 1

    squares.append([Perimeter, Area])
print(squares)

This works for what I'm doing so hopefully this might help others