python - Why is S == S[::-1] faster than looping? -

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why pythonic way of checking if string, s, palindrome -- s == s[::-1] -- faster following implementation?

i = 0 j = len(s) - 1 while < j:     if s[i] != s[j]:         return false     += 1     j -= 1 return true

because python code compiled bytecode, interpreted. that's going lot slower creating new reversed string in c code, comparing string string more c code.

note both algorithms o(n) complexity; python code executes @ 1/2 n iterations, , string reversal version makes @ 2 n iterations, asymptotically speaking doesn't make difference.

since both algorithms o(n) linear approaches, matters constant cost, how time each iteration takes. fixed cost vastly lower s == s[::-1].


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