Is it a good idea to check for odd/even length of a palindrome number/string? Most snippets I came across don't do this basic test. If length is even, it can't be a palindrome, no?
if len(var) % 2 != 0:
# could be a palindrome, continue...
else:
break
Or is it just better (i.e faster) to start comparing the first and last numbers/letters directly?
Edit: Okay, stupid question, should've thought twice! :)
Even length strings can be palindromes too. Wikipedia doesn't say anything about this restriction.
The easiest way to check for a palindrome is to simply compare the string against it's reverse:
def ispalindrome(s):
return s == s[::-1]
This uses extended slices with a negative step to walk backwards through s and get the reverse.
Try this:
is_palindrome = lambda s : all(s1==s2 for s1,s2 in zip(s[:len(s)/2],s[-1:-(len(s)+1)/2:-1]))
only checks the front half with the back half, and short-circuits as soon as a mismatch is found.
*n=raw_input("Enter a string==>")
n=int(n)
start=0
term=n
while n>0:
result=n%10
start=start*10+result
n=n/10
print start
if term==start: [link text][1] print "True"
else:
print "False"
[1]: http://rahimanpolindrom for srrings.com