Function _preprocess_single

src/betterproto/__init__.py:385–417

Adjusts values before serialization.

(proto_type: str, wraps: str, value: Any)

def _preprocess_single(proto_type: str, wraps: str, value: Any) -> bytes:
    """Adjusts values before serialization."""
    if proto_type in (
        TYPE_ENUM,
        TYPE_BOOL,
        TYPE_INT32,
        TYPE_INT64,
        TYPE_UINT32,
        TYPE_UINT64,
    ):
        return encode_varint(value)
    elif proto_type in (TYPE_SINT32, TYPE_SINT64):
        # Handle zig-zag encoding.
        return encode_varint(value << 1 if value >= 0 else (value << 1) ^ (~0))
    elif proto_type in FIXED_TYPES:
        return struct.pack(_pack_fmt(proto_type), value)
    elif proto_type == TYPE_STRING:
        return value.encode("utf-8")
    elif proto_type == TYPE_MESSAGE:
        if isinstance(value, datetime):
            # Convert the `datetime` to a timestamp message.
            value = _Timestamp.from_datetime(value)
        elif isinstance(value, timedelta):
            # Convert the `timedelta` to a duration message.
            value = _Duration.from_timedelta(value)
        elif wraps:
            if value is None:
                return b""
            value = _get_wrapper(wraps)(value=value)

        return bytes(value)

    return value


def _len_preprocessed_single(proto_type: str, wraps: str, value: Any) -> int: