3. Python的非正式介绍 An Informal Introduction to Python

In the following examples, input and output are distinguished by the presence or absence of prompts (">>> " and "... "): to repeat the example, you must type everything after the prompt, when the prompt appears; lines that do not begin with a prompt are output from the interpreter. Note that a secondary prompt on a line by itself in an example means you must type a blank line; this is used to end a multi-line command.

在后面的例子中，区分输入和输出的方法是看是否有提示符（"»> "和"... "）：想要重现这些例子的话，你就要在提示符显示后输入所有的一切；没有以提示符开始的行，是解释器输出的信息。需要注意的是示例中的从属提示符用于多行命令的结束，它表示你需要输入一个空行。

Many of the examples in this manual, even those entered at the interactive prompt, include comments. Comments in Python start with the hash character, "#", and extend to the end of the physical line. A comment may appear at the start of a line or following whitespace or code, but not within a string literal. A hash character within a string literal is just a hash character.

本手册中的很多示例都包括注释，甚至有一些在交互提示符中折行。Python中的注释以符号 "#" 起始，一直到当前行的结尾。注释可能出现在一行的开始，也可能跟在空格或程序代码之后，但不会出现在字符串中，字符串中的 # 号只代表 # 号。

Some examples: 示例：

# this is the first comment
SPAM = 1                 # and this is the second comment
                         # ... and now a third!
STRING = "# This is not a comment."