Behavior Notes

• Python 2

  • unicode type objects are packed into, and unpacked from, the MessagePack string format

  • str type objects are packed into, and unpacked from, the MessagePack binary format

• Python 3

  • str type objects are packed into, and unpacked from, the MessagePack string format

  • bytes type objects are packed into, and unpacked from, the MessagePack binary format

• The MessagePack string format is strictly decoded with UTF-8 — an exception is thrown if the string bytes cannot be decoded into a valid UTF-8 string, unless the allow_invalid_utf8 option is enabled

• The MessagePack array format is unpacked into a Python list, unless it is the key of a map, in which case it is unpacked into a Python tuple

• Python tuples and lists are both packed into the MessagePack array format

• Python float types are packed into the MessagePack float32 or float64 format depending on the system’s sys.float_info

• The Python datetime.datetime type is packed into, and unpacked from, the MessagePack timestamp format

  • Note that the Python datetime.datetime type only supports microsecond resolution, while the MessagePack timestamp format supports nanosecond resolution. Timestamps with finer than microsecond resolution will lose precision during unpacking. Users may override the packing and unpacking of the MessagePack timestamp format with a custom type for alternate behavior.

  • Both naive and aware timestamp are supported. Naive timestamps are packed as if they are in the UTC timezone. Timestamps are always unpacked as aware datetime.datetime objects in the UTC timezone.

• Ext type handlers specified in the optional ext_handlers dictionary will override ext_serializable() classes during packing and unpacking