Finding perfect numbers

# first solve simpler problem

def odd(n):
    '''
        return True if n is odd, otherwise return False
        exercise these tests using command
        
        SHELL_PROMPT$ python -m doctest -v this_file_name.py
        
        >>> odd(4)
        False
        >>> odd(19)
        True
    '''
    # your code fits here!


print('Odd numbers less than 10')
for number in range(10):
    if odd(number):
        print(number)

#
# A perfect number equals the sum of its proper factors.
#

def factor(n):
    '''
        return a list of the proper factors of n

        SHELL_PROMPT$ python -m doctest -v thisFile.py
        >>> factor(2)
        [1]
        >>> factor(5)
        [1]
        >>> factor(12)
        [1, 2, 3, 4, 6]
    '''
    # enter your factorization code here.
    # At least write down the steps you would take to factor a number by hand.

def perfect(n):
    '''
        determine if a number is perfect.
        return True if it is perfect, return False if it is not.
    '''
    factors = factor(n)
    return sum(factors) == n

print('perfect numbers')                # header
for number in range(1,1001):            # try all numbers from 1 to 1000
    if perfect(number):                 # if it is perfect, 
        print(number)                   #     print it.