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