You should return as soon as there is a mismatch. Also, you just need to iterate till half the length:
def function(...):
...
for i in range (0, (len(num) + 1) / 2):
if r[i] != num[i]:
return False
return True
BTW, you don't need that loop. You can simply do:
def palindrome(num):
return num == num[::-1]