🔒 reversing a stack?

[hearty grotto]

This is a linked list homework where I need to write a function to convert a string into another string depending on the contents of the original string (e.g. * = backspace, \ = enter, # = del whole line).

I'm given a class Stack with push() pop() and peek(), and I'm meant to use them to store the characters from the string into a stack and then return the stack to reveal the final output.

However when I return the stack, i get the reverse of the output that I am expecting, due to the FILO concept of stacks.

So, I tried to reverse the stack by creating another stack, but the output im getting is NoneNoneNoneNone... , I believe this is due pop() not actually pushing into the new stack? Perhaps I'm meant to use peek instead? I'm sure I'm missing something really obvious, but I cant seem to understand where I'm going wrong.

    reverse_stack = Stack()
    while not stack.isEmpty():
        reverse_stack.push(stack.pop())

    return reverse_stack

[gleaming moon]

@hearty grotto

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[proper dune]

hi

[tall crane]

well, stack.pop doesn't return the popped value with that implementation
maybe push the value in, then pop?

[hearty grotto]

i think i did it, the output is as expected finally

i did this instead with your suggestion:

    reverse_stack = Stack()
    while not stack.isEmpty():
        value = stack.peek()
        stack.pop()
        reverse_stack.push(value)

    return reverse_stack

i wonder if thats what you meant?

[tall crane]

ye
you could make it a teeny bit shorter by doing

    reverse_stack = Stack()
    while not stack.isEmpty():
        reverse_stack.push(stack.peek())
        stack.pop()
    return reverse_stack
```but it matters little

[hearty grotto]

oh i see, thanks very much!

[gleaming moon]

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🔒 reversing a stack?