Python 8.11 to 9 migration

You can do nothing and everything should still work when migrating to VW 9. But if you want to move to the new way to avoid deprecation warnings and future breaks here's a rundown.

Imports

Modules are now direcly accessible from the root module. In the past from vowpalwabbit import ... was needed, but now import vowpalwabbit and accessing with . will work.

pyvw

The old pyvw types are now available under the root module.

Instead of:

from vowpalwabbit import pyvw

Use:

import vowpalwabbit

And use the corresponding types exposed by {py:mod}vowpalwabbit instead of {py:mod}vowpalwabbit.pyvw.

{py:class}`vowpalwabbit.pyvw.SearchTask` is only available under {py:mod}`vowpalwabbit.pyvw` due to its advanced nature and less usage.

DFtoVW

Replace any reference to the old module name DFtoVW with {py:mod}vowpalwabbit.dftovw.

sklearn_vw

Replace any reference to the old module name sklearn_vw with {py:class}vowpalwabbit.sklearn.

Class names

• Replace {py:class}vowpalwabbit.pyvw.vw with {py:class}vowpalwabbit.Workspace
• Replace {py:class}vowpalwabbit.pyvw.example with {py:class}vowpalwabbit.Example
• Replace {py:class}vowpalwabbit.pyvw.example_namespace with {py:class}vowpalwabbit.ExampleNamespace
• Replace {py:class}vowpalwabbit.pyvw.namespace_id with {py:class}vowpalwabbit.NamespaceId
• Replace {py:class}vowpalwabbit.pyvw.abstract_label with {py:class}vowpalwabbit.AbstractLabel
• Replace {py:class}vowpalwabbit.pyvw.simple_label with {py:class}vowpalwabbit.SimpleLabel
• Replace {py:class}vowpalwabbit.pyvw.multiclass_label with {py:class}vowpalwabbit.MulticlassLabel
• Replace {py:class}vowpalwabbit.pyvw.multiclass_probabilities_label with {py:class}vowpalwabbit.MulticlassProbabilitiesLabel
• Replace {py:class}vowpalwabbit.pyvw.cost_sensitive_label with {py:class}vowpalwabbit.CostSensitiveLabel
• Replace {py:class}vowpalwabbit.pyvw.cbandits_label with {py:class}vowpalwabbit.CBLabel

get_prediction

Instead of calling the free function {py:func}vowpalwabbit.pyvw.get_prediction call {py:meth}vowpalwabbit.Example.get_prediction on an {py:class}vowpalwabbit.Example instance.

Label types and prediction types

• Instead of using the prediction type integer constants such as {py:const}vowpalwabbit.pyvw.pylibvw.vw.pSCALAR use the corresponding value in {py:class}vowpalwabbit.PredictionType
• Instead of using the label type integer constants such as {py:const}vowpalwabbit.pyvw.pylibvw.vw.lSimple use the corresponding value in {py:class}vowpalwabbit.LabelType
  • Instead of {py:const}vowpalwabbit.pyvw.pylibvw.vw.lBinary use {py:obj}vowpalwabbit.LabelType.SCALAR
  • Instead of {py:const}vowpalwabbit.pyvw.pylibvw.vw.lDefault use a value of None
  • {py:const}vowpalwabbit.pyvw.pylibvw.vw.lMax did not have a corresponding type

Getting a label from an Example

• If using {py:meth}vowpalwabbit.Example.get_label, you should change the parameter from a class type to a {py:class}vowpalwabbit.LabelType.
• If calling {py:meth}vowpalwabbit.AbstractLabel.from_example. This has changed from a method on an existing instance to a static factory function which accepts an {py:class}vowpalwabbit.Example and returns an instance of the correspodning label type. Using {py:meth}vowpalwabbit.Example.get_label is preferred.

ExampleNamespace.push_features

The first argument of {py:meth}vowpalwabbit.ExampleNamespace.push_features was removed as it was not needed and unused. Using two arguments is deprecated, to fix the callsites remove the first argument.