deep reverse.py

# Question 9: Deep Reverse
# Define a procedure, deep_reverse, that takes as input a list,
# and returns a new list that is the deep reverse of the input list.
# This means it reverses all the elements in the list, and if any
# of those elements are lists themselves, reverses all the elements
# in the inner list, all the way down.

# Note: The procedure must not change the input list.

# The procedure is_list below is from Homework 6. It returns True if
# p is a list and False if it is not.

def is_list(p):

    '''
    docstring
    '''

    return isinstance(p, list)


def deep_reverse(l):

    '''
    docstring
    '''

  # l.reverse()
  # for e in l:
  #   if is_list(e):
  #   deep_reverse(e)
  # return l
    if l == [] or type(l) == int or type(l) == str:
        return l
    else:
        return deep_reverse(l[1:]) + [deep_reverse(l[0])]


#For example,

p = [1, [2, 3, [4, [5, 6]]]]
print(deep_reverse(p))
#>>> [[[[6, 5], 4], 3, 2], 1]
print(p)
#>>> [1, [2, 3, [4, [5, 6]]]]

q =  [1, [2,3], 4, [5,6]]
print(deep_reverse(q))
#>>> [ [6,5], 4, [3, 2], 1]
print(q)
#>>> [1, [2,3], 4, [5,6]]