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