Leetcode Valid palindrome Python

Valid palindrome 

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.

For example,
"A man, a plan, a canal: Panama"is a palindrome.
"race a car"is not a palindrome.

Note:
Are you consider that the string might is empty? This was a good question to ask during a interview.

For the purpose of this problem, we define empty string as valid palindrome.

classSolution:#@param s, a string    #@return A Boolean    defIspalindrome (self, s): LS= [I.lower () forIinchSifI.isalnum ()] L=len (LS) tmp1= LS[:L/2] TMP2= List (Reversed (LS[L/2:]ifL%2==0ElseLs[l/2+1:])) returnTrueifTmp1==tmp2ElseFalse

Leetcode Valid palindrome Python