le(obj))
    ['foo']

If *base_type* is set, objects for which ``isinstance(obj, base_type)``
returns ``True`` won't be considered iterable.

    >>> obj = {'a': 1}
    >>> list(always_iterable(obj))  # Iterate over the dict's keys
    ['a']
    >>> list(always_iterable(obj, base_type=dict))  # Treat dicts as a unit
    [{'a': 1}]

Set *base_type* to ``None`` to avoid any special handling and treat objects
Python considers iterable as iterable:

    >>> obj = 'foo'
    >>> list(always_iterable(obj, base_type=None))
    ['f', 'o', 'o']
r³