def append_recursive()

in watchman/python/pywatchman/pybser.py [0:0]
84 lines of code
21 McCabe index (conditional complexity)

    def append_recursive(self, val):
        if isinstance(val, bool):
            needed = 1
            self.ensure_size(needed)
            if val:
                to_encode = BSER_TRUE
            else:
                to_encode = BSER_FALSE
            struct.pack_into(b"=c", self.buf, self.wpos, to_encode)
            self.wpos += needed
        elif val is None:
            needed = 1
            self.ensure_size(needed)
            struct.pack_into(b"=c", self.buf, self.wpos, BSER_NULL)
            self.wpos += needed
        elif isinstance(val, (int, long)):
            self.append_long(val)
        elif isinstance(val, STRING_TYPES):
            self.append_string(val)
        elif isinstance(val, float):
            needed = 9
            self.ensure_size(needed)
            struct.pack_into(b"=cd", self.buf, self.wpos, BSER_REAL, val)
            self.wpos += needed
        elif isinstance(val, collections_abc.Mapping) and isinstance(
            val, collections_abc.Sized
        ):
            val_len = len(val)
            size = _int_size(val_len)
            needed = 2 + size
            self.ensure_size(needed)
            if size == 1:
                struct.pack_into(
                    b"=ccb", self.buf, self.wpos, BSER_OBJECT, BSER_INT8, val_len
                )
            elif size == 2:
                struct.pack_into(
                    b"=cch", self.buf, self.wpos, BSER_OBJECT, BSER_INT16, val_len
                )
            elif size == 4:
                struct.pack_into(
                    b"=cci", self.buf, self.wpos, BSER_OBJECT, BSER_INT32, val_len
                )
            elif size == 8:
                struct.pack_into(
                    b"=ccq", self.buf, self.wpos, BSER_OBJECT, BSER_INT64, val_len
                )
            else:
                raise RuntimeError("Cannot represent this mapping value")
            self.wpos += needed
            iteritems = val.items()
            for k, v in iteritems:
                self.append_string(k)
                self.append_recursive(v)
        elif isinstance(val, collections_abc.Iterable) and isinstance(
            val, collections_abc.Sized
        ):
            val_len = len(val)
            size = _int_size(val_len)
            needed = 2 + size
            self.ensure_size(needed)
            if size == 1:
                struct.pack_into(
                    b"=ccb", self.buf, self.wpos, BSER_ARRAY, BSER_INT8, val_len
                )
            elif size == 2:
                struct.pack_into(
                    b"=cch", self.buf, self.wpos, BSER_ARRAY, BSER_INT16, val_len
                )
            elif size == 4:
                struct.pack_into(
                    b"=cci", self.buf, self.wpos, BSER_ARRAY, BSER_INT32, val_len
                )
            elif size == 8:
                struct.pack_into(
                    b"=ccq", self.buf, self.wpos, BSER_ARRAY, BSER_INT64, val_len
                )
            else:
                raise RuntimeError("Cannot represent this sequence value")
            self.wpos += needed
            for v in val:
                self.append_recursive(v)
        else:
            raise RuntimeError("Cannot represent unknown value type")