def accumulator(init, update):
return (<EOL>init + len(update)<EOL>if isinstance(init, int) else<EOL>init + update<EOL>)<EOL>
Generic accumulator function.

.. code-block:: python

    # Simplest Form
    >>> a = 'this' + ' '
    >>> b = 'that'
    >>> c = functools.reduce(accumulator, a, b)
    >>> c
    'this that'

    # The type of the initial value determines output type.
    >>> a = 5
    >>> b = Hello
    >>> c = functools.reduce(accumulator, a, b)
    >>> c
    10

:param init:  Initial Value
:param update: Value to accumulate

:return: Combined Values