[Tutor] Error message...

[Mark Lawrence]

On 23/08/2012 15:17, Victoria Homsy wrote:
> Dear all,
>
> Sorry to bother you with a beginner's problem again...

You're welcome as that's what we're here for.

>
> I have tried to write a program that can check if a string is a palindrome. My code is as follows:
>
>
> def isPalindrome(s):
> if len(s) <= 1: return True
> else: return s(0) == s(-1) and isPalindrome (s[1:-1])
> isPalindrome('aba')
>
>
> However, when I try to run it in terminal I get the following error message:
>
> Traceback (most recent call last):
>    File "recursion.py", line 5, in <module>
>      isPalindrome('aba')
>    File "recursion.py", line 3, in isPalindrome
>      else: return s(0) == s(-1) and isPalindrome (s[1:-1])
> TypeError: 'str' object is not callable
>
>
> I don't see why this wouldn't work...

Always easier for another pair of eyes.  The TypeError tells you exactly 
what the problem is.  Just look very carefully at the return after the 
else and compare your use of the function parameter s.  Then kick 
yourself and have another go :)

>
> Many thanks in advance.
>
> Kind regards,
>
> Victoria
>
>
>
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-- 
Cheers.

Mark Lawrence.