Is it possible to turn a list into a nested dict of keys *without* recursion?

Question

Supposing I had a list as follows:

mylist = ['a','b','c','d']

Is it possible to create, from this list, the following dict without using recursion/a recursive function?

{
  'a': {
    'b': {
      'c': {
        'd': { }
      }
    }
  }
}

Answer 1

For the simple case, simply iterate and build, either from the end or the start:

result = {}
for name in reversed(mylist):
    result = {name: result}

or

result = current = {}
for name in mylist:
    current[name] = {}
    current = current[name]

The first solution can also be expressed as a one-liner using reduce():

reduce(lambda res, name: {name: res}, reversed(mylist), {})

Answer 2

For this simple case at least, yes:

my_list = ['a', 'b', 'c', 'd']
cursor = built_dict = {}
for value in my_list:
    cursor[value] = {}
    cursor = cursor[value]

Answer 3

Or for fancyness and reduced readability:

dict = reduce(lambda x, y: {y: x}, reversed(myList), {})