Input and Variables (Python)

Well today I learned a lot, starting with python I learned how to read variables in python for example I can type any letter and then what I want the letter to be as the result for example " a = 123" then I retyped a and it gives me the value which would be "123" as a result.
then if I want to write it in a script then first I write the values and then I print it out and it would come out the value.