tutorial introduction note if you try the preceding example and it fails with syntaxerroryou are probably using python if this is the caseyou can continue to follow along with this but be aware that the print statement turned into function in python simply add parentheses around the items to be printed in the examples that follow for instanceprint("hello world"hello world putting parentheses around the item to be printed also works in python as long as you are printing just single item howeverit' not syntax that you commonly see in existing python code in later this syntax is sometimes used in examples in which the primary focus is feature not directly related to printingbut where the example is supposed to work with both python and python' interactive mode is one of its most useful features in the interactive shellyou can type any valid statement or sequence of statements and immediately view the results many peopleincluding the authoreven use interactive python as their desktop calculator for example when you use python interactivelythe special variable holds the result of the last operation this can be useful if you want to save or use the result of the last operation in subsequent statements howeverit' important to stress that this variable is only defined when working interactively if you want to create program that you can run repeatedlyput statements in file such as the followinghelloworld py print "hello worldpython source files are ordinary text files and normally have py suffix the character denotes comment that extends to the end of the line to execute the helloworld py fileyou provide the filename to the interpreter as followspython helloworld py hello world on windowspython programs can be started by double-clicking py file or typing the name of the program into the run command on the windows start menu this launches the interpreter and runs the program in console window howeverbe aware that the console window will disappear immediately after the program completes its execution (often before you can read its outputfor debuggingit is better to run the program within python development tool such as idle on unixyou can use #on the first line of the programlike this#!/usr/bin/env python print "hello worldf lib fl ff