def is_palindrome(num):
    s = int(math.log10(num)+1)  # 正数数字长度
    if s == 1:
        return False

    def get_v(i):
        return int((num % (10 ** i)) / 10 ** (i-1))
    x, y = s, 1
    while True:
        if get_v(num, x) == get_v(num, y):
            x -= 1
            y += 1
        else:
            return False

        if x <= y:
            return True

output = filter(is_palindrome, range(1, 1000))
print(list(output))