[BUG]: plot_model(et, plot='tree') not displaying Tree

[aledeper]

pycaret version checks

• I have checked that this issue has not already been reported here.

• I have confirmed this bug exists on the latest version of pycaret.

• I have confirmed this bug exists on the master branch of pycaret (pip install -U git+https://github.com/pycaret/pycaret.git@master).

Issue Description

I can't plot the decision tree for a model based on trees like Extra Trees with the latest version of PyCaret

Reproducible Example

et = create_model('et')
plot_model(et, plot='tree')

Expected Behavior

The tree is shown.

Actual Results

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
~\AppData\Local\Temp\ipykernel_25768\3791440483.py in <module>
----> 1 plot_model(et, plot='tree')

~\AppData\Roaming\Python\Python39\site-packages\pycaret\utils\generic.py in wrapper(*args, **kwargs)
    962                 if globals_d[name] is None:
    963                     raise ValueError(message)
--> 964             return func(*args, **kwargs)
    965 
    966         return wrapper

~\AppData\Roaming\Python\Python39\site-packages\pycaret\classification\functional.py in plot_model(estimator, plot, scale, save, fold, fit_kwargs, plot_kwargs, groups, verbose, display_format)
   1723     """
   1724 
-> 1725     return _CURRENT_EXPERIMENT.plot_model(
   1726         estimator=estimator,
   1727         plot=plot,

~\AppData\Roaming\Python\Python39\site-packages\pycaret\classification\oop.py in plot_model(self, estimator, plot, scale, save, fold, fit_kwargs, plot_kwargs, groups, verbose, display_format)
   2069         """
   2070 
-> 2071         return super().plot_model(
   2072             estimator=estimator,
   2073             plot=plot,

~\AppData\Roaming\Python\Python39\site-packages\pycaret\internal\pycaret_experiment\tabular_experiment.py in plot_model(self, estimator, plot, scale, save, fold, fit_kwargs, plot_kwargs, groups, feature_name, label, verbose, display_format)
   2043 
   2044         """
-> 2045         return self._plot_model(
   2046             estimator=estimator,
   2047             plot=plot,

~\AppData\Roaming\Python\Python39\site-packages\pycaret\internal\pycaret_experiment\tabular_experiment.py in _plot_model(self, estimator, plot, scale, save, fold, fit_kwargs, plot_kwargs, groups, feature_name, label, verbose, system, display, display_format)
   1911                 # execute the plot method
   1912                 with redirect_output(self.logger):
-> 1913                     ret = locals()[plot]()
   1914                 if ret:
   1915                     plot_filename = ret

~\AppData\Roaming\Python\Python39\site-packages\pycaret\internal\pycaret_experiment\tabular_experiment.py in tree()
   1522                             trees = [fitted_estimator]
   1523                     if self._ml_usecase == MLUsecase.CLASSIFICATION:
-> 1524                         class_names = list(class_names.values())
   1525                     for i, tree in enumerate(trees):
   1526                         self.logger.info(f"Plotting tree {i}")

AttributeError: 'NoneType' object has no attribute 'values'

Installed Versions

Pycaret 3.3.0 matplotlib 3.6.0 numpy 1.23.0

[celestinoxp]

@aledeper what version of sktime? try with 0.26.0 and give me feedback, please

[aledeper]

@celestinoxp 0.027.0, I have tried with version 0.26.0 and I get the same error