What does that angle brackets mean?

[NewPi]

Hi,

thanks for your answer.

But I have another question. I used mro() to see the whole inheritance of AxesSubplot. And I wondered about "_subplots", "_base" and "_axes":

%matplotlib inline
import matplotlib.pyplot as plt
hist_diagram = housing.hist(bins=50, figsize=(20, 15))
print(type(hist_diagram[0][0]).mro())

Output:
[<class 'matplotlib.axes._subplots.AxesSubplot'>, <class 'matplotlib.axes._subplots.SubplotBase'>, <class 'matplotlib.axes._axes.Axes'>, <class 'matplotlib.axes._base._AxesBase'>, <class 'matplotlib.artist.Artist'>, <class 'object'>]

In the docs of matplotlib I can see there is a class named "matplotlib.axes.SubplotBase", but not a class names "matplotlib.axes._subplots.SubplotBase". What does this _subplots stand for?