Python 基础一（String 处理）

阿牛

　　Python 里面 String的处理：
　　1.基本的‘和“处理，不用多说，直接上例子：

>>> 'spam eggs'
'spam eggs'
>>> 'doesn\'t'
"doesn't"
>>> "doesn't"
"doesn't"
>>> '"Yes," he said.'
'"Yes," he said.'
>>> "\"Yes,\" he said."
'"Yes," he said.'
>>> '"Isn\'t," she said.'
'"Isn\'t," she said.'
　　2. String 对象可以被简单重复 

>>> word = 'Help' + 'A'
>>> '<' + word*5 + '>'
'<HelpAHelpAHelpAHelpAHelpA>'
　　3.python的substring 比较好用。index是从0开始，像word[0]

>>> word = 'Help' + 'A'
>>> word[4]
'A'
>>> word[0:2]
'He'
>>> word[2:4]
'lp'
>>> word[:2]    # The first two characters
'He'
>>> word[2:]    # Everything except the first two characters
'lpA'
　　但对String里面的substring直接赋值却不行。