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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 compute_path(self):
 """ Compute the min cost path between the two waves, and return it. Return the computed path as a tuple with two elements, each being a :class:`numpy.ndarray` (1D) of ``int`` indices: :: where ``r_i`` are the indices in the real wave and ``s_i`` are the indices in the synthesized wave, and ``k`` is the length of the min cost path. Return ``None`` if the accumulated cost matrix cannot be computed because one of the two waves is empty after masking (if requested). :rtype: tuple (see above) :raises: RuntimeError: if both the C extension and the pure Python code did not succeed. """

        self._setup_dtw()
        if self.dtw is None:
            self.log(u"Inner self.dtw is None => returning None")
            return None
        self.log(u"Computing path...")
        wave_path = self.dtw.compute_path()
        self.log(u"Computing path... done")
        self.log(u"Translating path to full wave indices...")
        real_indices = numpy.array([t[0] for t in wave_path])
        synt_indices = numpy.array([t[1] for t in wave_path])
        if self.rconf.mmn:
            self.log(u"Translating real indices with masked_middle_map...")
            real_indices = self.real_wave_mfcc.masked_middle_map[real_indices]
            real_indices[0] = self.real_wave_mfcc.head_length
            self.log(u"Translating real indices with masked_middle_map... done")
            self.log(u"Translating synt indices with masked_middle_map...")
            synt_indices = self.synt_wave_mfcc.masked_middle_map[synt_indices]
            self.log(u"Translating synt indices with masked_middle_map... done")
        else:
            self.log(u"Translating real indices by adding head_length...")
            real_indices += self.real_wave_mfcc.head_length
            self.log(u"Translating real indices by adding head_length... done")
            self.log(u"Nothing to do with synt indices")
        self.log(u"Translating path to full wave indices... done")
        return (real_indices, synt_indices)