1 2.. _library-intro: 3 4************ 5Introduction 6************ 7 8The "Python library" contains several different kinds of components. 9 10It contains data types that would normally be considered part of the "core" of a 11language, such as numbers and lists. For these types, the Python language core 12defines the form of literals and places some constraints on their semantics, but 13does not fully define the semantics. (On the other hand, the language core does 14define syntactic properties like the spelling and priorities of operators.) 15 16The library also contains built-in functions and exceptions --- objects that can 17be used by all Python code without the need of an :keyword:`import` statement. 18Some of these are defined by the core language, but many are not essential for 19the core semantics and are only described here. 20 21The bulk of the library, however, consists of a collection of modules. There are 22many ways to dissect this collection. Some modules are written in C and built 23in to the Python interpreter; others are written in Python and imported in 24source form. Some modules provide interfaces that are highly specific to 25Python, like printing a stack trace; some provide interfaces that are specific 26to particular operating systems, such as access to specific hardware; others 27provide interfaces that are specific to a particular application domain, like 28the World Wide Web. Some modules are available in all versions and ports of 29Python; others are only available when the underlying system supports or 30requires them; yet others are available only when a particular configuration 31option was chosen at the time when Python was compiled and installed. 32 33This manual is organized "from the inside out:" it first describes the built-in 34data types, then the built-in functions and exceptions, and finally the modules, 35grouped in chapters of related modules. The ordering of the chapters as well as 36the ordering of the modules within each chapter is roughly from most relevant to 37least important. 38 39This means that if you start reading this manual from the start, and skip to the 40next chapter when you get bored, you will get a reasonable overview of the 41available modules and application areas that are supported by the Python 42library. Of course, you don't *have* to read it like a novel --- you can also 43browse the table of contents (in front of the manual), or look for a specific 44function, module or term in the index (in the back). And finally, if you enjoy 45learning about random subjects, you choose a random page number (see module 46:mod:`random`) and read a section or two. Regardless of the order in which you 47read the sections of this manual, it helps to start with chapter 48:ref:`built-in-funcs`, as the remainder of the manual assumes familiarity with 49this material. 50 51Let the show begin! 52 53