How to use the fiona.FIELD_TYPES_MAP.items function in fiona

def write_shapefile(data, postcode_sector_name, filename):

    # Translate props to Fiona sink schema
    prop_schema = []
    for name, value in data[0]['properties'].items():
        fiona_prop_type = next((
            fiona_type for fiona_type, python_type in \
                fiona.FIELD_TYPES_MAP.items() if \
                python_type == type(value)), None
            )

        prop_schema.append((name, fiona_prop_type))

    sink_driver = 'ESRI Shapefile'
    sink_crs = {'init': 'epsg:27700'}
    sink_schema = {
        'geometry': data[0]['geometry']['type'],
        'properties': OrderedDict(prop_schema)
    }

    # Create path
    directory = os.path.join(DATA_INTERMEDIATE,
        'system_simulator', postcode_sector_name)
    if not os.path.exists(directory):

for node_id, node in list(self._network.nodes('object')):
            if node != None:
                geom_list.setdefault(str(type(node)),[]).append(node)

        for origin, dest in list(self._network.edges()):
            link_obj = self._network[origin][dest]['object']
            geom_list.setdefault(str(type(link_obj)),[]).append(link_obj)
        
        # Write nodes to output
        for key in geom_list.keys():

            # Translate props to Fiona sink schema
            prop_schema = []
            for name, value in geom_list[key][0].props.items():
                fiona_prop_type = next((fiona_type for fiona_type, python_type in fiona.FIELD_TYPES_MAP.items() if python_type == type(value)), None)
                prop_schema.append((name, fiona_prop_type))

            sink_schema = {
                'geometry': geom_list[key][0].geom.type,
                'properties': OrderedDict(prop_schema)
            }

            # Write all elements to output file
            with fiona.open(os.path.join(directory, key[8:-2] + '.shp'), 'w', driver=sink_driver, crs=sink_crs, schema=sink_schema) as sink:
                for node in geom_list[key]:
                    sink.write({
                        'geometry': mapping(node.geom),
                        'properties': OrderedDict(node.props)
                    })

def write_single_exchange_shapefile(data, path):

    prop_schema = []

    for name, value in data[0]['properties'].items():
        fiona_prop_type = next((fiona_type for fiona_type, python_type in fiona.FIELD_TYPES_MAP.items() if python_type == type(value)), None)
        prop_schema.append((name, fiona_prop_type))

    sink_driver = 'ESRI Shapefile'
    sink_crs = {'init': 'epsg:27700'}
    sink_schema = {
        'geometry': data[0]['geometry']['type'],
        'properties': OrderedDict(prop_schema)
    }

    # Write all elements to output file
    with fiona.open(path, 'w', driver=sink_driver, crs=sink_crs, schema=sink_schema) as sink:
        [sink.write(feature) for feature in data]

def get_fiona_type(value):
    for fiona_type, python_type in fiona.FIELD_TYPES_MAP.items():
        if python_type == type(value):
            return fiona_type
    return None

def write_shapefile(data, path, crs):

    # Translate props to Fiona sink schema
    prop_schema = []
    for name, value in data[0]['properties'].items():
        fiona_prop_type = next((fiona_type for fiona_type, python_type in fiona.FIELD_TYPES_MAP.items() if python_type == type(value)), None)
        prop_schema.append((name, fiona_prop_type))

    sink_driver = 'ESRI Shapefile'
    sink_crs = {'init':crs}
    sink_schema = {
        'geometry': data[0]['geometry']['type'],
        'properties': OrderedDict(prop_schema)
    }

    # Write all elements to output file
    with fiona.open(path, 'w', driver=sink_driver, crs=sink_crs, schema=sink_schema) as sink:
        for feature in data:
            sink.write(feature)