variablesexpressionsand statements type(' 'type(' 'they're strings when you type large integeryou might be tempted to use commas between groups of three digitsas in , , this is not legal integer in pythonbut it is legalprint( , , wellthat' not what we expected at allpython interprets , , as commaseparated sequence of integerswhich it prints with spaces between this is the first example we have seen of semantic errorthe code runs without producing an error messagebut it doesn' do the "rightthing variables one of the most powerful features of programming language is the ability to manipulate variables variable is name that refers to value an assignment statement creates new variables and gives them valuesmessage 'and now for something completely differentn pi this example makes three assignments the first assigns string to new variable named messagethe second assigns the integer to nthe third assigns the (approximatevalue of to pi to display the value of variableyou can use print statementprint( print(pi the type of variable is the type of the value it refers to type(messagetype(ntype(pi