rapid introduction to procedural programming result--and this may not be boolean (although it can be converted to boolean)not always returns either true or false we can test for membership of sequence typesincluding stringslistsand tuplesusing the in and not in operators membership testing uses slow linear search on lists and tuplesand potentially much faster hybrid algorithm for stringsbut performance is rarely an issue except for very long stringslistsand tuples in we will learn about python' associative array and set collection data typesboth of which provide very fast membership testing it is also possible to find out an object variable' type ( the type of object the object reference refers tousing type()--but this function is normally used only for debugging and testing python provides several control structuresincluding conditional branching with if elif elseconditional looping with whilelooping over sequences with for inand exception-handling with try except blocks both while and for in loops can be prematurely terminated using break statementand both can switch control to the beginning using continue the usual arithmetic operators are supportedincluding +-*and /although python is unusual in that always produces floating-point result even if both its operands are integers (the truncating division that many other languages use is also available in python as /python also provides augmented assignment operators such as +and *=these create new objects and rebind behind the scenes if their left-hand operand is immutable the arithmetic operators are overloaded by the str and list types as we noted earlier console / can be achieved using input(and print()and using file redirection in the consolewe can use these same built-in functions to read and write files in addition to python' rich built-in functionalityits extensive standard library is also availablewith modules accessible once they have been imported using the import statement one commonly imported module is syswhich holds the sys argv list of command-line arguments and when python doesn' have the function we need we can easily create one that does what we want using the def statement by making use of the functionality described in this it is possible to write short but useful python programs in the following we will learn more about python' data typesgoing into more depth for ints and strs and introducing some entirely new data types in we will learn more about tuples and listsand also about some of python' other collection data types thenin we will cover python' control structures in much more detailand will learn how to create our own functions so that we can package up functionality to avoid code duplication and promote code reuse