palindrome iteration

Jussi Piitulainen jpiitula at ling.helsinki.fi
Fri Aug 27 16:51:17 EDT 2010


MRAB writes:
> On 27/08/2010 20:43, Jussi Piitulainen wrote:
>> Dave Angel writes:
>>> Jussi Piitulainen wrote:
>>>> Agreed. But is there any nicer way to spell .reverse than [::-1]
>>>> in Python? There is .swapcase() but no .reverse(), right?
>>>>
>>> There can't be a .reverse() method on string, because it's
>>> immutable. You could use
>>>
>>>      "".join(reversed(pal))
>>>
>>> but I'd prefer  pal[::-1]  as I said earlier.
>>
>> There could easily be a .reverse() method on strings. It would
>> return the reversed string, like .swapcase() returns the swapcased
>> string.
> 
> Lists have a .reverse method, but it's an in-place reversal. In
> order to reduce confusion, a string method which returned the string
> reversed would be better called .reversed().

Yes, agreed.

Meanwhile, I have decided to prefer this:

def palindromep(s):
    def reversed(s):
        return s[::-1]
    return s == reversed(s)



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