Added a bit about global variables

Python/002_globals.py

@@ -0,0 +1,34 @@
+# Global Scope
+
+# We will discuss scope in the context of functions and classes
+# at a later point.
+
+# More detailed reading: https://realpython.com/python-constants/
+
+# The "scope" of anything (variable, function, etc.) means
+# "where is this thing available".
+
+# For this initial introduction we will only be discussing
+# the "global scope". Global means "available everywhere".
+# Anything defined in the global scope can be accessed in
+# the main part of the program, inside the body/blocks of
+# a function, and from within classes.
+
+# Any variable declared in the top part of the program is
+# technically a global variable and can be accessed anywhere.
+# However, it is (usually) considered bad form to change global
+# variable values inside functions and classes.
+
+# We use a special notation to define global variables which
+# are intended to hold values for settings and such.
+# Create them using all capital letters. Visual Studio Code
+# will actually color these slighly differently so it is obvious.
+
+MAX_LOOPS = 500
+
+loop_count = 0
+
+# Notice that these two variables are slightly different colors.
+# Nothing prevents you from changing the value of an all upper
+# case variable, but the convention of using all caps is meant
+# to indicate that the value SHOULDN'T be changed.