目的

　　獲得一個(gè)首尾不含多余空格的字符串

方法

可以使用字符串的以下方法處理：

string.lstrip(s[, chars])
Return a copy of the string with leading characters removed. If chars is omitted or None, whitespace characters are removed. If given and not None, chars must be a string; the characters in the string will be stripped from the beginning of the string this method is called on.

string.rstrip(s[, chars])
Return a copy of the string with trailing characters removed. If chars is omitted or None, whitespace characters are removed. If given and not None, chars must be a string; the characters in the string will be stripped from the end of the string this method is called on.

string.strip(s[, chars])
Return a copy of the string with leading and trailing characters removed. If chars is omitted or None, whitespace characters are removed. If given and not None, chars must be a string; the characters in the string will be stripped from the both ends of the string this method is called on.

具體的效果如下：
代碼如下:
In [10]: x='     Hi,Jack!        '

In [11]: print '|',x.lstrip(),'|',x.rstrip(),'|',x.strip(),'|'
| Hi,Jack!         |      Hi,Jack! | Hi,Jack! |

其中提供的參數(shù)chars用來刪除特定的符號(hào)，注意空格并沒有被移除，例如：
代碼如下:
In [12]: x='yxyxyxxxyy Hello xyxyxyy'

In [13]: print x.strip('xy')
 Hello