Python-thing-recursion-wonderings.py

recur_even_odd_list_split.py

l1 = [1,3,9,10,4,3,2,5,17,14,11]

def splitIt(x):
    '''
    This recursive function takes a list of positive integers
    x as argument and returns a tuple of two lists: a list of the even integers
    in x followed by a list of the odd integers in x.

    E.g. x = [3,2,1,5,4,6] gives [1,3,5] [2,4,6]
    x = [1,3,9] gives [1,3,9] []
    '''
    # shell function for setting up variables that can be called again.
    even_list = []
    odd_list = []

    recursive_even_odd_lists_generator(x, even_list, odd_list)

    return (even_list, odd_list)

def number_is_odd(num):
    if num % 2 != 0:
        return True

def recursive_even_odd_lists_generator(x, even_list, odd_list):
    # check to see if position 1 (or list[0]) is even or odd. If even, append to even_list. Else append to odd_list.
    x_first = x[0]

    if number_is_odd(x_first):
        # add to odd list
        odd_list.append(x_first)
    else:
        print("item is even" + str(x))
        # add to even list
        even_list.append(x_first)
        print("even list " + str(even_list))

    if len(x) == 1:
        return x

    return (recursive_even_odd_lists_generator(x[1:], even_list, odd_list))