7 examples of 'palindrome program in python without using string functions' in Python

21
def isPalindrome(string):
22
    leftIdx = 0
23
    rightIdx = len(string) - 1
24
    while leftIdx < rightIdx:
25
        if string[leftIdx] != string[rightIdx]:
26
            return False
27
        leftIdx += 1
28
        rightIdx -= 1
29
    return True

13
def isPalindromeIterative(string):
14
    start = 0
15
    end = len(string) - 1
16
    while start < end:
17
        start = start + 1
18
        end = end - 1
19
        if string[start] != string[end]:
20
            return False
21
    return True

35
def isPalindrome(self, A):
36
    low, high = 0, len(A) - 1
37
    while low < high:
38
39
        while low < high and not A[low].isalnum():
40
            low += 1
41
42
        while low < high and not A[high].isalnum():
43
            high -= 1
44
45
        if A[low].lower() != A[high].lower():
46
            return 0
47
48
        low, high = low + 1, high - 1
49
50
    return 1

174
def test_is_palindrome(self):
175
    # 'Otto' is a old german name.
176
    self.assertTrue(is_palindrome("Otto"))
177
    self.assertFalse(is_palindrome("house"))

14
def isPalindrome(self, s):
15
    """
16
    :type s: str
17
    :rtype: bool
18
    """
19
    cleaned = re.sub('[^0-9a-zA-Z]', '', s)
20
    if cleaned.lower() == cleaned[::-1].lower():
21
        return True
22
    return False

31
@staticmethod
32
def is_palindrome(num):
33
    return str(num) == ''.join(reversed(str(num)))

34
def isPalindrome(self, s: 'str') -> 'bool':
35
    s = ''.join(filter(str.isalnum, s)).lower()
36
    return s == s[::-1]