Python Tutorial
Release 2.4
Guido van Rossum
Fred L. Drake, Jr., editor
December 21, 2004
Python Software Foundation
Email: docs@python.org
Copyright c° 2001-2004 Python Software Foundation. All rights reserved.
Copyright c° 2000 BeOpen.com. All rights reserved.
Copyright c° 1995-2000 Corporation for National Research Initiatives. All rights reserved.
Copyright c° 1991-1995 Stichting Mathematisch Centrum. All rights reserved.
See the end of this document for complete license and permissions information.
Abstract
Python is an easy to learn, powerful programming language. It has efficient high-level data structures and a simple
but effective approach to object-oriented programming. Python’s elegant syntax and dynamic typing, together with its
interpreted nature, make it an ideal language for scripting and rapid application development in many areas on most
platforms. Python
是一种容易学习的强大语言。它包括了高效的高级数据结构，提供了一个简单但很有效的方式进行面向对
象编程。Python 优雅的语法，动态类型，以及它天然的解释能力，使其成为了大多数平台上应用于各领域
理想的脚本语言以及开发环境。
The Python interpreter and the extensive standard library are freely available in source or binary form for all major
platforms from the Python Web site, http://www.python.org/, and can be freely distributed. The same site also contains
distributions of and pointers to many free third party Python modules, programs and tools, and additional documenta-
tion.
Python 解释器及其扩展标准库的源码和编译版本可以从Python 的Web 站点, http://www.python.org/, 及其所有
镜像站上免费获得，并且可以自由发布。该站点上也提供了Python 的一些第三方模块，程序，工具，以及
附加的文档。
The Python interpreter is easily extended with new functions and data types implemented in C or C++ (or other
languages callable from C). Python is also suitable as an extension language for customizable applications.
Python 的解释器很容易通过C 或C++ （或者其它可以由C来调用的语言）来扩展新的函数和数据结构。因
此Python 也很适于作为定制应用的一种扩展语言。
This tutorial introduces the reader informally to the basic concepts and features of the Python language and system. It
helps to have a Python interpreter handy for hands-on experience, but all examples are self-contained, so the tutorial
can be read off-line as well.
这个手册介绍了一些Python 语言及其系统的基本知识与概念。这有助于读者对Python 有一个基本的认识，
当然所有的例子都已包括在文中，所以这本手册很适合离线阅读。
For a description of standard objects and modules, see the Python Library Reference document. The Python Refer-
ence Manual gives a more formal definition of the language. To write extensions in C or C++, read Extending and
Embedding the Python Interpreter and Python/C API Reference. There are also several books covering Python in
depth.
需要有关标准对象和模块的详细介绍的话，请查询Python 库参考手册 文档。Python 参考手册 提供了更多的
关于语言方面的正式说明。需要编写C或C++扩展，请阅读Python 解释器的扩展和集成 以及Python/C API 参
考手册。这几本书涵盖了各个深度上的Python知识。
This tutorial does not attempt to be comprehensive and cover every single feature, or even every commonly used
feature. Instead, it introduces many of Python’s most noteworthy features, and will give you a good idea of the
language’s flavor and style. After reading it, you will be able to read and write Python modules and programs, and you
will be ready to learn more about the various Python library modules described in the Python Library Reference.
本手册不会涵盖Python 的所有功能，也不会去解释所用到的所有相关的知识。相反，它介绍了许多Python
中最引人注目的功能，这会对读者掌握这门语言的风格大有帮助。读过它后，你应该可以阅读和编写Python
模块和程序，接下来可以从Python 库参考手册 中进一步学习Python复杂多变的库和模块。
CONTENTS
1 Whetting Your Appetite 1
2 Using the Python Interpreter 3
2.1 调用解释器Invoking the Interpreter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2 解释器及其环境The Interpreter and Its Environment . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Python简简简介介介An Informal Introduction to Python 9
3.1 将Python当作计算器使用Using Python as a Calculator . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 开始编程First Steps Towards Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4 More Control Flow Tools 23
4.1 if 语句if Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.2 for 语句for Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.3 range() 函数The range() Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.4 break 和continue 语句, 以及循环中的else 子句break and continue Statements, and
else Clauses on Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.5 pass 语句pass Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.6 Defining Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.7 深入函数定义More on Defining Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5 Data Structures 35
5.1 深入链表More on Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.2 del 语句 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.3 元组（Tuples）和序列（Sequences ）Tuples and Sequences . . . . . . . . . . . . . . . . . . . . 41
5.4 Dictionaries 字典 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.5 循环技巧Looping Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5.6 深入条件控制More on Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.7 比较序列和其它类型Comparing Sequences and Other Types . . . . . . . . . . . . . . . . . . . . . 45
6 Modules 47
6.1 深入模块More on Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6.2 标准模块Standard Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
6.3 dir() 函数dir() Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
6.4 包Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
7 Input and Output 59
7.1 设计输出格式Fancier Output Formatting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
7.2 读写文件Reading and Writing Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
8 Errors and Exceptions 67
i
