今日阅读：【17个新手常见Python运行时错误】http://www.dedecms.com/knowledge/program/other/2012/0731/4046.html
今日学习：
1. \n 输出的是换行
2.输出string时要注意引号的
3.如果要用%r,%s输出string,不用用逗号隔开。
eg: days=‘Monday Tuesday Wedesday Thuseday Friday Saturday Sunday’
print"Here are the days:%r" %days
4.如果输出string有用到换行\n关键字,用%s输出有换行效果,但如果用%r,则是直接输出\n字符,无换行效果。
5.输出的“”“。。”“” 三引号的用法要注意一下。用三引号输出的话，就是里面的string语句可以有很多句。可以自定格式。
6.【\的使用】输出的string中如果有会引起系统误会的字符,则在此符号前使用\，那么它就会按原样输出了。（这个在C里好像叫转义符号）
7.【Escape Sequences】
This is the list of all of the escape sequences Python supports. You may not use many of these, but memorize their format and what they do anyway. Also try them out in some strings to see if you can make them work.
| Escape | What it does. |
|---|---|
| \\ | Backslash () |
| \' | Single quote (') |
| \" | Double quote (") |
| \a | ASCII Bell (BEL) |
| \b | ASCII Backspace (BS) |
| \f | ASCII Formfeed (FF) |
| \n | ASCII Linefeed (LF) |
| \N{name} | Character named name in the Unicode database (Unicode only) |
| \r ASCII | Carriage Return (CR) |
| \t ASCII | Horizontal Tab (TAB) |
| \uxxxx | Character with 16-bit hex value xxxx (Unicode only) |
| \Uxxxxxxxx | Character with 32-bit hex value xxxxxxxx (Unicode only) |
| \v | ASCII Vertical Tab (VT) |
| \ooo | Character with octal value ooo |
| \xhh | Character with hex value hh |
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【Most programming errors in the beginning (and even later) are simple spelling mistakes, typos, or getting simple things out of order.】
【Periodically go through your notes and see if you can figure these things out after you've completed more exercises. Sometimes though you may need to go back a few exercises and go through them again.】
【Always remember this: %r is for debugging, %s is for displaying.】