Finding the Number of Steps to make a Palindromic String

def palindrome(s):
    no = 0

    if s == s[::-1]:
        return no

    else:
        if (len(s)%2 != 0):
            mid = int((len(s)+1)/2)-1
            s_for, s_rev = list(s[:mid]), list((s[mid+1:])[::-1])
        else:
            mid = int(len(s)/2)
            s_for, s_rev = list(s[:mid]), list((s[mid:])[::-1])

        i = 0

        for i in range(len(s_rev)):
            rev_char = s_rev[i]
            for_char = s_for[i]
            diff_ord = abs(ord(rev_char) - ord(for_char))

            no += diff_ord

        return no

val = palindrome("abc")
print(val)