Doc/lib/libintro.tex

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