python - Palindrome with Recursion -


i'm trying make more advanced palindrome according docstring. can't work. going right way? have far:

def pal_length(s: str, n: int) -> bool:   '''return true iff s has palindrome of length n.    >>> pal_length('abclevel', 5)   true   >>> pal_length('level', 2)   false   '''   if not s:       return true   else:       index = 0       while index < len(s):           if s[index] == s[index+n]:               return pal_length(s[index+1:index+n-1],n-1)           index += 1   return false

i'm trying not use import modules etc. straight recursion.

any appreciated. thanks.

i think indexing bit off. shouldn't be

index = 0 while index < len(s) - n + 1:     if s[index] == s[index+n-1]:         return pal_length(s[index+1:index+n-1], n-2)     index += 1 return false

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