On this page: variables, variable assignment statement using =, incrementing an integer variable with +=, valid Python variable names.
Interactive shell output for this tutorial is found here.
To set the value of a variable, type the character(s) you want followed by "=" and then the desired value. Ex: x = 5. The variable "x" will now have the value of "5" until specified otherwise.
Non mathematical values, such as a string of characters, are also allowed in Python. Ex: x = 'red'. if this line is entered, x will have a value of 'red' until specified otherwise. In addition, longer variable names are allowed in Python, so assignments such as red = 13 and _typ = 'red' are also valid.
To increment the value of a variable, type the variable followed by "+=" and then the amount you wish to add, Ex: x += 1. If the value of "x" was originally at 5, the new value will now be 6.
Python variable names can contain any alphabetic characters (A-Z and a-z), digits (0-9), and the underscore character "_". There are some caveats and restrictions:
Uppercase and lowercase letters are distinct. Therefore, Number and number are two different variables.
A digit cannot start a variable name. Therefore, student1 is a valid variable, while 1student is not.
Built-in keywords and function names shouldn't be used as a variable name. For example, print is obviously a Python keyword, therefore you shouldn't be using it as your variable name.