How to use the cclib.parser.utils.PeriodicTable function in cclib

def setUp(self):
        self.t = utils.PeriodicTable()

def testcorrect(self):
        """Is coreelectrons equal to what it should be?"""
        pt = PeriodicTable()
        ans = []
        for x in self.data.atomnos:
            ans.append(self.coredict[pt.element[x]])
        ans = numpy.array(ans, "i")
        numpy.testing.assert_array_equal(self.data.coreelectrons, ans)

def setUp(self):
        self.pt = cclib.parser.utils.PeriodicTable()

def after_parsing(self):
        """NWChem-specific routines for after parsing a file.

        Currently, expands self.shells() into self.aonames.
        """

        # setup a few necessary things, including a regular expression
        # for matching the shells
        table = utils.PeriodicTable()
        elements = [table.element[x] for x in self.atomnos]
        pattern = re.compile("(\ds)+(\dp)*(\dd)*(\df)*(\dg)*")

        labels = {}
        labels['s'] = ["%iS"]
        labels['p'] = ["%iPX", "%iPY", "%iPZ"]
        if self.shells['type'] == 'spherical':
            labels['d'] = ['%iD-2', '%iD-1', '%iD0', '%iD1', '%iD2']
            labels['f'] = ['%iF-3', '%iF-2', '%iF-1', '%iF0',
                           '%iF1', '%iF2', '%iF3']
            labels['g'] = ['%iG-4', '%iG-3', '%iG-2', '%iG-1', '%iG0',
                           '%iG1', '%iG2', '%iG3', '%iG4']
        elif self.shells['type'] == 'cartesian':
            labels['d'] = ['%iDXX', '%iDXY', '%iDXZ',
                           '%iDYY', '%iDYZ',
                           '%iDZZ']

def symbol2int(symbol):
    t = utils.PeriodicTable()
    return t.number[symbol]

def before_parsing(self):
        self.geoopt = False # Is this a GeoOpt? Needed for SCF targets/values.
        self.periodic_table = utils.PeriodicTable()

def stoichiometry(self):
        """Return the stoichemistry of the object according to the Hill system"""
        cclib_pt = PeriodicTable()
        elements = [cclib_pt.element[ano] for ano in self.data.atomnos]
        counts = {el: elements.count(el) for el in set(elements)}

        formula = ""
        elcount = lambda el, c: "%s%i" % (el, c) if c > 1 else el
        if 'C' in elements:
            formula += elcount('C', counts['C'])
            counts.pop('C')
            if 'H' in elements:
              formula += elcount('H', counts['H'])
              counts.pop('H')
        for el, c in sorted(counts.items()):
            formula += elcount(el, c)

        if getattr(self.data, 'charge', 0):
            magnitude = abs(self.data.charge)