python allowed variable caracters

Letters: A-Z, a-z
Digits: 0-9		# the first character of a variable name cannot be a digit
And the underscore character _

Here is what the above code is Doing:
1. We create a variable called x and assign it the value of 5.
2. We create a variable called y and assign it the value of 3.
3. We create a variable called z and assign it the value of x + y.
4. We print out the value of z.