an implied subject in functions within class in sensethoughthe class-based type simply builds on and uses core types-- user-defined worker object herefor exampleis just collection of string and number (name and payrespectively)plus functions for processing those two built-in objects the larger story of classes is that their inheritance mechanism supports software hierarchies that lend themselves to customization by extension we extend software by writing new classesnot by changing what already works you should also know that classes are an optional feature of pythonand simpler built-in types such as lists and dictionaries are often better tools than user-coded classes this is all well beyond the bounds of our introductory object-type tutorialthoughso consider this just previewfor full disclosure on user-defined types coded with classesyou'll have to read on because classes build upon other tools in pythonthey are one of the major goals of this book' journey and everything else as mentioned earliereverything you can process in python script is type of objectso our object type tour is necessarily incomplete howevereven though everything in python is an "object,only those types of objects we've met so far are considered part of python' core type set other types in python either are objects related to program execution (like functionsmodulesclassesand compiled code)which we will study lateror are implemented by imported module functionsnot language syntax the latter of these also tend to have application-specific roles--text patternsdatabase interfacesnetwork connectionsand so on moreoverkeep in mind that the objects we've met here are objectsbut not necessarily object-oriented-- concept that usually requires inheritance and the python class statementwhich we'll meet again later in this book stillpython' core objects are the workhorses of almost every python script you're likely to meetand they usually are the basis of larger noncore types summary and that' wrap for our initial data type tour this has offered brief introduction to python' core object types and the sorts of operations we can apply to them we've studied generic operations that work on many object types (sequence operations such as indexing and slicingfor example)as well as type-specific operations available as method calls (for instancestring splits and list appendswe've also defined some key termssuch as immutabilitysequencesand polymorphism along the waywe've seen that python' core object types are more flexible and powerful than what is available in lower-level languages such as for instancepython' lists and dictionaries obviate most of the work you do to support collections and introducing python object types