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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 _get_bond_data(line):
 """ Subroutine to extract bond label, site indices, and length from a COPL header line. The site indices are zero-based, so they can be easily used with a Structure object. Example header line: Fe-1/Fe-1-tr(-1,-1,-1) : 2.482 Ang. Args: line: line in the COHPCAR header describing the bond. Returns: The bond label, the bond length and a tuple of the site indices. """


        line = line.split()
        length = float(line[2])
        # Replacing "/" with "-" makes splitting easier
        sites = line[0].replace("/", "-").split("-")
        site_indices = tuple(int(ind) - 1 for ind in sites[1:4:2])
        species = tuple(re.split(r"\d+", spec)[0] for spec in sites[0:3:2])
        label = "%s%d-%s%d" % (species[0], site_indices[0] + 1,
                               species[1], site_indices[1] + 1)
        return label, length, site_indices