How to use the hl7apy.utils.iteritems function in hl7apy

def reduce_content_size(self, content):
        to_delete = []
        for key, value in iteritems(content):
            if value is not None:
                if isinstance(value, list):
                    continue
                if value['type'] in ('sequence', 'choice') and value.get('content'):
                    try:
                        new_value = (value['type'],  # TODO: can we set only sequence?
                                     tuple((x['ref'], (x.get('min', 0), x.get('max', -1))) for x in value['content']))
                    except:
                        new_value = None
                elif value['type'] == 'annotation':
                    new_value = ('leaf', value['datatype'], value.get('libraryLongName'), value.get('table'))
                else:
                    new_value = None
                if new_value is None:
                    to_delete.append(key)
                else:

output_file.write("}\n")

            output_file.write("for k, v in GROUPS.iteritems():\n")
            output_file.write("    for item in v[1]:\n")
            output_file.write("        if item[3] == 'GRP':\n")
            output_file.write("            item[1] = GROUPS[item[0]]\n")

        parse_res = self.parse_schema("messages.xsd")
        content, message_files = parse_res[0], parse_res[1]
        message_def = {}
        groups = {}
        for f in message_files:  # each file describes an HL7 message
            message, ext = os.path.splitext(f)
            content = self.parse_schema(f)[0]
            message_def[message] = content[message.upper()]
            groups.update(g for g in iteritems(content) if g[0] != message)
        self.generate_module("messages.py", message_def, ["groups", "segments"], message_writer)
        self.generate_module("groups.py", groups, ["segments"], groups_writer)

('XTN_6', DATATYPES['XTN_6'], (0, 1), 'CMP'),
           ('XTN_7', DATATYPES['XTN_7'], (0, 1), 'CMP'),
           ('XTN_8', DATATYPES['XTN_8'], (0, 1), 'CMP'),
           ('XTN_9', DATATYPES['XTN_9'], (0, 1), 'CMP'),
           ('XTN_10', DATATYPES['XTN_10'], (0, 1), 'CMP'),
           ('XTN_11', DATATYPES['XTN_11'], (0, 1), 'CMP'),
           ('XTN_12', DATATYPES['XTN_12'], (0, 1), 'CMP'),
           ('XTN_13', DATATYPES['XTN_13'], (0, 1), 'CMP'),
           ('XTN_14', DATATYPES['XTN_14'], (0, 1), 'CMP'),
           ('XTN_15', DATATYPES['XTN_15'], (0, 1), 'CMP'),
           ('XTN_16', DATATYPES['XTN_16'], (0, 1), 'CMP'),
           ('XTN_17', DATATYPES['XTN_17'], (0, 1), 'CMP'),
           ('XTN_18', DATATYPES['XTN_18'], (0, 1), 'CMP'),),
}

for k, v in iteritems(DATATYPES):
    if v[0] == 'sequence':
        v[1] = DATATYPES_STRUCTS[v[2]]

'XTN': (
           ('XTN_1', DATATYPES['XTN_1'], (0, 1), 'CMP'),
           ('XTN_2', DATATYPES['XTN_2'], (0, 1), 'CMP'),
           ('XTN_3', DATATYPES['XTN_3'], (0, 1), 'CMP'),
           ('XTN_4', DATATYPES['XTN_4'], (0, 1), 'CMP'),
           ('XTN_5', DATATYPES['XTN_5'], (0, 1), 'CMP'),
           ('XTN_6', DATATYPES['XTN_6'], (0, 1), 'CMP'),
           ('XTN_7', DATATYPES['XTN_7'], (0, 1), 'CMP'),
           ('XTN_8', DATATYPES['XTN_8'], (0, 1), 'CMP'),
           ('XTN_9', DATATYPES['XTN_9'], (0, 1), 'CMP'),
           ('XTN_10', DATATYPES['XTN_10'], (0, 1), 'CMP'),
           ('XTN_11', DATATYPES['XTN_11'], (0, 1), 'CMP'),
           ('XTN_12', DATATYPES['XTN_12'], (0, 1), 'CMP'),),
}

for k, v in iteritems(DATATYPES):
    if v[0] == 'sequence':
        v[1] = DATATYPES_STRUCTS[v[2]]

def _find_structure(self, reference=None):
        if self.name is not None:
            structure = ElementFinder.get_structure(self, reference)
            for k, v in iteritems(structure):
                setattr(self, k, v)

def _find_structure(self, reference=None):
        if self.name is not None or reference is not None:
            structure = ElementFinder.get_structure(self, reference)
            for k, v in iteritems(structure):
                setattr(self, k, v)