Edit this code snippet to reverse a string in Python without using the built-in reverse function or slicing. The input string may contain spaces and punctuation marks.

def reverse_string(s):
    reversed_string = ""
    for i in range(len(s)-1, -1, -1):
        if s[i].isalpha():
            reversed_string += s[i]
    return reversed_string

#Additional Reasoning Steps#
1. Initialize a variable 'reversed_string' as an empty string to store the reversed string.
2. Start a for loop from the last index of the input string 's' to the first index, iterating backwards.
3. Check if the character at the current index is an alphabet using the 'isalpha()' method.
4. If the character is an alphabet, append it to the 'reversed_string' variable.
5. Continue the loop until all characters in the input string have been checked.
6. Return the 'reversed_string' as the final result.
def reverse_string(s):
    reversed_string = ""
    for i in range(len(s)-1, -1, -1):
        reversed_string += s[i]
    return reversed_string

#Additional Reasoning Steps#
1. Initialize a variable 'reversed_string' as an empty string to store the reversed string.
2. Start a for loop from the last index of the input string 's' to the first index, iterating backwards.
3. Append each character at the current index to the 'reversed_string' variable.
4. Continue the loop until all characters in the input string have been checked.
5. Return the 'reversed_string' as the final result.

Note: The if statement checking if the character is an alphabet is removed since we want to reverse the string regardless of its contents.