Exception in Tkinter callback using SHAP

Question

I'm trying to draw some SHAP plots in Python to gain a deeper understanding of the output of my machine learning models. This is the method I'm calling in a for loop:

def plotAndSaveSHAPSummary(model,train_data,x_train,pathToSHAPPlots):
    shap_values = model.get_feature_importance(train_data, type='ShapValues')
    expected_value = shap_values[0,-1]
    shap_values = shap_values[:,:-1]

    shap.summary_plot(shap_values,x_train,max_display=20,show=False)
    plt.savefig(pathToSHAPPlots+'/SHAP Plots/SHAP_Plot'+str(counter)+'.png',dpi=300,bbox_inches='tight')
    plt.clf()

The plots are saved to the disk as expected but after each call of the savefig method, I get the following error message:

Exception in Tkinter callback
Traceback (most recent call last):
  File "D:\PathTo\Anaconda\Lib\tkinter\__init__.py", line 1705, in __call__
    return self.func(*args)
  File "D:\PathTo\Anaconda\Lib\tkinter\__init__.py", line 749, in callit
    func(*args)
  File "D:\PathTo\Anaconda\lib\site-packages\matplotlib\backends\_backend_tk.py", line 270, in idle_draw
    self.draw()
  File "D:\PathTo\Anaconda\lib\site-packages\matplotlib\backends\backend_tkagg.py", line 9, in draw
    super(FigureCanvasTkAgg, self).draw()
  File "D:\PathTo\Anaconda\lib\site-packages\matplotlib\backends\backend_agg.py", line 393, in draw
    self.figure.draw(self.renderer)
  File "D:\PathTo\Anaconda\lib\site-packages\matplotlib\backend_bases.py", line 1535, in _draw
    def _draw(renderer): raise Done(renderer)
matplotlib.backend_bases._get_renderer.<locals>.Done: <matplotlib.backends.backend_agg.RendererAgg object at 0x000002066B288288>

Any ideas how to get rid of this exception?

Answer 1

I started getting this error too after update of one of the libs, probably matplot lib. The suggestion to use plt.pause described in the comment worked but it is internally calling plt.show() which was unacceptable for me. I ended up adding canvas.start_event_loop just before the savefig

import sys

def _save(self, filename: str) -> None:
   fig1 = plt.gcf()
   fig1.set_size_inches(6, 2.8)
   plt.draw()
   fig1.subplots_adjust(left=0.20)
   fig1.canvas.start_event_loop(sys.float_info.min) #workaround for Exception in Tkinter callback
   fig1.savefig(self.dst_dir + '/' + filename + '.png', dpi=220, bbox_inches='tight')
   fig1.clf()
   plt.close()