Doc/lib/libintro.tex

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