Why doesn't my code generate random numbers without str?

Question

Can someone explain to me why when I remove 'str' from 7 line of code "myset.add(str(i))", do I get the same numbers every time I hit run and get random numbers with 'str' included?

def RandomFunction(x, y):
    myset = set()
    mylist = []
    listofnumbers = []

    for i in range(x, y):
        myset.add(str(i))
    for x in myset:
        mylist.append(int(x))

    if len(mylist) <= 5:
        print('In order to generate 5 numbers, the range of input needs to be higher')
    else:
        for y in mylist:
            listofnumbers.append(y)
            if len(listofnumbers) >= 5:
                print(listofnumbers)
                break


RandomFunction(10, 20)

Answer 1

Set keeps the elements in hash table, it uses default python's hash() function. Its implementation for numeric types looks like this:

def hash(number):
    return number % (2 ** 61 - 1)

So, if the numbers aren't huge, hash value of an integer will be equal to the same integer. Because of this integers in python's set will be kept in ascending order ( for also reads hash table in ascending order).

But string is a sequense of unicode characters with \0 at the end and python has another implementation of hash() for strings, so it won't work the same way for them.