human
Can you provide a the Python code you requested given the following:
Complete the below
def countby(key, seq):

    ''''Count elements of a collection by a key function
    >>> countby(len, [\'cat\', \'mouse\', \'dog\'])
    {3: 2, 5: 1}
    >>> def iseven(x): return x % 2 == 0
    >>> countby(iseven, [1, 2, 3])  # doctest:+SKIP
    {True: 1, False: 2}
    See Also:
    groupby'
    '''
assistant
#Here is the Python code you requested.
    if (not callable(key)):
        key = getter(key)
    return frequencies(map(key, seq))