principal eval(input("enter the initial principal")apr eval(input("enter the annual interest rate")for in range( )principal principal ( aprprint("the value in years is:"principalmain(notice that have added few blank lines to separate the inputprocessingand output portions of the program strategically placed "white spacecan help make your programs more readable that' as far as ' taking this examplei leave the testing and debugging as an exercise for you summary this has covered lot of ground laying out both the process that is used to develop programs and the details of python that are necessary to implement simple programs here is quick summary of some of the key pointswriting programs requires systematic approach to problem solving and involves the following steps problem analysisstudying the problem to be solved program specificationdeciding exactly what the program will do designwriting an algorithm in pseudocode implementationtranslating the design into programming language testing/debuggingfinding and fixing errors in the program maintenancekeeping the program up to date with evolving needs many simple programs follow the inputprocessoutput (ipopattern programs are composed of statements that are built from identifiers and expressions identifiers are namesthey begin with an underscore or letter which can be followed by combination of letterdigitor underscore characters identifiers in python are case sensitive expressions are the fragments of program that produce data an expression can be composed of the following componentsliterals literal is representation of specific value for example is literal representing the number three