save: saving custom models

[aguschin]

I'd like to have a way to serialize custom models. I know I just could implement something like class CustomModel(ModelType, ModelHook, IsInstanceHookMixin) and use it as a plugin, but would be good to have some built-in way of doing that.

Last thing I tried was this, but it doesn't work (in the sense that upon model loading whichtype and metrics are disconnected and calling whichtypes doesn't increase the counter returned by metrics.

from mlem.core.objects import MlemModel, ModelAnalyzer


class Model:
    times_called = 0
    
    def whichtype(self, data):
        self.times_called += 1
        return str(type(data))
    
    def metrics(self, dummyarg):
        return self.times_called


simple_model = Model()
    

model = MlemModel()
model.add_processor("whichtype", ModelAnalyzer.analyze(simple_model.whichtype, sample_data="word"))
model.add_processor("metrics", ModelAnalyzer.analyze(simple_model.metrics, sample_data="word"))
model.call_orders["whichtype"] = [("whichtype", "__call__")]
model.call_orders["metrics"] = [("metrics", "__call__")]

model.dump("model")

Few ideas how this can look like

from mlem.bla.bla import modelmethoddecorator

class Model:
    times_called = 0
    
    @modelmethoddecorator
    def whichtype(self, data):
        self.times_called += 1
        return str(type(data))
    
    @modelmethoddecorator
    def metrics(self, dummyarg):
        self.times_called += 1
        return self.times_called

or

from mlem.bla.bla import modelmethoddecorator

class Model:
    _model_methods=["whichtypes", "metrics"]
    times_called = 0
    
    def whichtype(self, data):
        self.times_called += 1
        return str(type(data))
    
    def metrics(self, dummyarg):
        self.times_called += 1
        return self.times_called

or just

mlem.api.save(model, methods=["whichtypes", "metrics"])

or

mlem.api.save(model, sample_data={"whichtypes": (["word"], {}), "metrics": ({dummyarg="value"})])