true and as assert break def del elif else except from global if import in nonlocal not or pass raise while with yield identifiers in programming languagesidentifiers are names used to identify variablefunctionor other entities in program the rules for naming an identifier in python are as followsthe name should begin with an uppercase or lowercase alphabet or an underscore sign (_this may be followed by any combination of characters -za- - or underscore (_thusan identifier cannot start with digit it can be of any length (howeverit is preferred to keep it short and meaningfulit should not be keyword or reserved word given in table we cannot use special symbols like !@#$%etc in identifiers for exampleto find the average of marks obtained by student in three subjectswe can choose the identifiers as marks marks marks and avg rather than abcor abc avg (marks marks marks )/ similarlyto calculate the area of rectanglewe can use identifier namessuch as arealengthbreadth instead of single alphabets as identifiers for clarity and more readability area length breadth variables variable in program is uniquely identified by name (identifiervariable in python refers to an object -an item or element that is stored in the memory value of variable can be string ( ' ''global citizen')numeric ( or any combination of alphanumeric characters (cd in python we can use an assignment statement to create new variables and assign specific values to them - notes