|"|&|<|>等html字符转义
参见：http://blog.****.net/wusuopubupt/article/details/8817826
场景：
写爬虫的时候，遇到 |"|&|<|&g
| No. | 文字表記 | 10進表記 | 16進表記 | 文字 | Comment | |
|---|---|---|---|---|---|---|
| 001 | " | " | " | """ | quotation mark = APL quote | |
| 002 | & | & | & | "&" | ampersand | |
| 003 | < | < | < | "<" | less-than sign | |
| 004 | > | > | > | ">" | greater-than sign | |
| 005 | |   |   | " " | no-break space = non-breaking space |