PEP-563 breaks SerializationStrategy about mashumaro HOT 8 CLOSED

I changed the way howSerializationStrategy classes are used. @rominf you might be interested in reading README here and here. At the moment these changes are in the master branch but I will release 2.0 version soon since it's not backward compatible.

from mashumaro.

perhaps a better approach is to use separate serialization annotations. i.e.:

@dataclass
class DateTimeFormats(DataClassDictMixin):
    @FormattedDateTime(fmt='%d%m%Y%H%M%S') 
    short:datetime
    @FormattedDateTime(fmt='%A %B %d, %Y, %H:%M:%S')
    verbose:datetime

from mashumaro.

from future import annotations
from mashumaro import DataClassJSONMixin

@DataClass
class aClass(DataClassJSONMixin):
mem_t: member_TT # un declare

@DataClass
class member_TT(DataClassJSONMixin):
pass

produces

File "/i/t/miniconda/lib/python3.7/site-packages/mashumaro/serializer/base/dict.py", line 19, in init_subclass
raise exc
File "/i/t/miniconda/lib/python3.7/site-packages/mashumaro/serializer/base/dict.py", line 15, in init_subclass
builder.add_to_dict()
File "/i/t/miniconda/lib/python3.7/site-packages/mashumaro/serializer/base/metaprogramming.py", line 163, in add_to_dict
for fname, ftype in self.fields.items():
File "/i/t/miniconda/lib/python3.7/site-packages/mashumaro/serializer/base/metaprogramming.py", line 53, in fields
for fname, ftype in typing.get_type_hints(self.cls).items():
File "/i/t/miniconda/lib/python3.7/typing.py", line 976, in get_type_hints
value = _eval_type(value, base_globals, localns)
File "/i/t/miniconda/lib/python3.7/typing.py", line 263, in _eval_type
return t._evaluate(globalns, localns)
File "/i/t/miniconda/lib/python3.7/typing.py", line 467, in _evaluate
eval(self.forward_code, globalns, localns),
File "", line 1, in
NameError: name 'member_TT' is not defined

from mashumaro.

It breaks my program in Python 3.8 too. I would consider this as a bug, but not an enhancement.

Are there plans to fix this?

from mashumaro.

perhaps a better approach is to use separate serialization annotations. i.e.:

@dataclass
class DateTimeFormats(DataClassDictMixin):
    @FormattedDateTime(fmt='%d%m%Y%H%M%S') 
    short:datetime
    @FormattedDateTime(fmt='%A %B %d, %Y, %H:%M:%S')
    verbose:datetime

The current implementation of SerializationStrategy is a dirty hack that won't work in Python 3.10. At this moment I'm working on improving the customization capabilities of mashumaro and I think I can replace SerializationStrategy with something like this:

@dataclass
class DateTimeFormats(DataClassDictMixin):
    short: datetime = field(
        default_factory=datetime.now,
        metadata={
            "serialization_strategy": FormattedDateTime("%d%m%Y%H%M%S")
        },
    )
    verbose: datetime = field(
        default_factory=datetime.now,
        metadata={
            "serialization_strategy": FormattedDateTime("%A %B %d, %Y, %H:%M:%S")
        },
    )

Since in would break backward compatibility I could do it in version 2.x. But anyway with upcoming changes in this library you can do the same things from the example even without SerializationStrategy:

@dataclass
class DateTimeFormats(DataClassDictMixin):
    short: datetime = field(
        default_factory=datetime.now,
        metadata={
            'deserialize':
                lambda s: datetime.strptime(s, '%d%m%Y%H%M%S')
        }
    )
    verbose: datetime = field(
        default_factory=datetime.now,
        metadata={
            'deserialize':
                lambda s: datetime.strptime(s, '%A %B %d, %Y, %H:%M:%S')
        }
    )

or with SerializationStrategy if you'd like:

@dataclass
class DateTimeFormats(DataClassDictMixin):
    short: datetime = field(
        default_factory=datetime.now,
        metadata={
            'deserialize': FormattedDateTime("%d%m%Y%H%M%S")._deserialize
        }
    )
    verbose: datetime = field(
        default_factory=datetime.now,
        metadata={
            'deserialize': FormattedDateTime("%A %B %d, %Y, %H:%M:%S")._deserialize
        }
    )

I haven't done serialize option yet but it's definitely needed and will be done soon. Also from this point of view serialization_strategy option in metadata would be no more than syntax sugar that would allow you not to define both serialize and deserialize options.

So, if anyone is interested in SerializationStrategy suggestions and discussion are welcome.

from mashumaro.

from future import annotations
from mashumaro import DataClassJSONMixin

@DataClass
class aClass(DataClassJSONMixin):
mem_t: member_TT # un declare

@DataClass
class member_TT(DataClassJSONMixin):
pass

@dand-oss your example is about another known problem with forward references #28

from mashumaro.

It breaks my program in Python 3.8 too. I would consider this as a bug, but not an enhancement.

Are there plans to fix this?

It's not a bug but a hacky feature that should be reimplemented in another way :)

from mashumaro.

The new changes are in 2.0 now.

from mashumaro.