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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def natsorted(seq, key=None, reverse=False, alg=ns.DEFAULT):
 """ Sorts an iterable naturally. Parameters seq : iterable The input to sort. key : callable, optional A key used to determine how to sort each element of the iterable. It is **not** applied recursively. It should accept a single argument and return a single value. reverse : {{True, False}}, optional Return the list in reversed sorted order. The default is `False`. alg : ns enum, optional This option is used to control which algorithm `natsort` uses when sorting. For details into these options, please see the :class:`ns` class documentation. The default is `ns.INT`. Returns ------- out: list The sorted input. See Also -------- natsort_keygen : Generates the key that makes natural sorting possible. realsorted : A wrapper for ``natsorted(seq, alg=ns.REAL)``. humansorted : A wrapper for ``natsorted(seq, alg=ns.LOCALE)``. index_natsorted : Returns the sorted indexes from `natsorted`. Examples -------- Use `natsorted` just like the builtin `sorted`:: [{u}'num2', {u}'num3', {u}'num5'] """

    key = natsort_keygen(key, alg)
    return sorted(seq, reverse=reverse, key=key)