L23Q4_DeepCount.py

# Deep Count

# The built-in len operator outputs the number of top-level elements in a List,
# but not the total number of elements. For this question, your goal is to count
# the total number of elements in a list, including all of the inner lists.

# Define a procedure, deep_count, that takes as input a list, and outputs the
# total number of elements in the list, including all elements in lists that it
# contains.


# For this procedure, you will need a way to test if a value is a list. We have
# provided a procedure, is_list(p) that does this:

def is_list(p):
    return isinstance(p, list)

# It is not necessary to understand how is_list works. It returns True if the
# input is a List, and returns False otherwise.
count = [0]
def deep_count(p):
    count[0]+= len(p)
    #print count,'count'
    for i in p:
        if type(i) != int: #check if it's a list
            deep_count(i)
    return count[0]

def deep_count_udacity(p):
    sum = 0
    for i in p:
        sum += 1
        if is_list(i):
            sum += deep_count_udacity(i)
    return sum


#print deep_count([1, 2, 3])
#>>> 3

# The empty list still counts as an element of the outer list
print deep_count([1, [], 3])
#>>> 3

print deep_count_udacity([1, [1, 2, [3, 4]]])
#>>> 7

print deep_count_udacity([[[[[[[[1, 2, 3]]]]]]]])
#>>> 10