identifiers and keywords integral types floating-point types strings |||data types in this we begin to take much more detailed look at the python language we start with discussion of the rules governing the names we give to object referencesand provide list of python' keywords then we look at all of python' most important data types--excluding collection data typeswhich are covered in the data types considered are all built-inexcept for one which comes from the standard library the only difference between builtin data types and library data types is that in the latter casewe must first import the relevant module and we must qualify the data type' name with the name of the module it comes from-covers importing in depth identifiers and keywords object references ||when we create data item we can either assign it to variableor insert it into collection (as we noted in the preceding when we assign in pythonwhat really happens is that we bind an object reference to refer to the object in memory that holds the data the names we give to our object references are called identifiers or just plain names valid python identifier is nonempty sequence of characters of any length that consists of "start characterand zero or more "continuation characterssuch an identifier must obey couple of rules and ought to follow certain conventions the first rule concerns the start and continuation characters the start character can be anything that unicode considers to be letterincluding the ascii letters (" "" "" "" "" "" ")the underscore (" ")as well as the letters from most non-english languages each continuation character can be any character that is permitted as start characteror pretty well any nonwhitespace characterincluding any character that unicode considers to be digitsuch as (" "" "" ")or the catalan character "*identifiers are case