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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 parse_number_factory(alg, sep, pre_sep):
 """ Create a function that will format a number into a tuple. Parameters alg : ns enum Indicate how to format the *bytes*. sep : str The string character to be inserted before the number in the returned tuple. pre_sep : str In the event that *alg* contains ``UNGROUPLETTERS``, this string will be placed in a single-element tuple at the front of the returned nested tuple. Returns ------- func : callable A function that accepts numeric input (e.g. *int* or *float*) and returns a tuple containing the number with the leading string *sep*. Intended to be used as the *num_func* argument to *natsort_key*. See Also -------- natsort_key """

    nan_replace = float("+inf") if alg & ns.NANLAST else float("-inf")

    def func(val, _nan_replace=nan_replace, _sep=sep):
        """Given a number, place it in a tuple with a leading null string."""
        return _sep, _nan_replace if val != val else val

    # Return the function, possibly wrapping in tuple if PATH is selected.
    if alg & ns.PATH and alg & ns.UNGROUPLETTERS and alg & ns.LOCALEALPHA:
        return lambda x: (((pre_sep,), func(x)),)
    elif alg & ns.UNGROUPLETTERS and alg & ns.LOCALEALPHA:
        return lambda x: ((pre_sep,), func(x))
    elif alg & ns.PATH:
        return lambda x: (func(x),)
    else:
        return func