Update Python version in the doc examples

Author: oscargus

doc/users/installing/index.rst

@@ -304,9 +304,9 @@ at the Terminal.app command line::
 
 You should see something like ::
 
-  3.0.0 /Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/matplotlib/__init__.py
+  3.6.0 /Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/matplotlib/__init__.py
 
-where ``3.0.0`` is the Matplotlib version you just installed, and the path
+where ``3.6.0`` is the Matplotlib version you just installed, and the path
 following depends on whether you are using Python.org Python, Homebrew or
 Macports.  If you see another version, or you get an error like ::
 

tutorials/introductory/customizing.py

@@ -217,8 +217,8 @@ def plotting_function():
 #
 # 4. :file:`{INSTALL}/matplotlib/mpl-data/matplotlibrc`, where
 #    :file:`{INSTALL}` is something like
-#    :file:`/usr/lib/python3.7/site-packages` on Linux, and maybe
-#    :file:`C:\\Python37\\Lib\\site-packages` on Windows. Every time you
+#    :file:`/usr/lib/python3.9/site-packages` on Linux, and maybe
+#    :file:`C:\\Python39\\Lib\\site-packages` on Windows. Every time you
 #    install matplotlib, this file will be overwritten, so if you want
 #    your customizations to be saved, please move this file to your
 #    user-specific matplotlib directory.