input: Write a function in Python to determine if a given string is a palindrome.
  
  ### Input:
  def isPalindrome(s):
      return s == s[::-1]
      
  ### Output:
  assert isPalindrome("racecar") == True
  assert isPalindrome("hello") == False
  assert isPalindrome("madam") == True
  assert isPalindrome("a") == True
  assert isPalindrome("") == True
output: def isPalindrome(s):
      return s == s[::-1]