Python3基础 str : 对字符串进行切片

   Python : 3.7.3

   OS : Ubuntu 18.04.2 LTS

  IDE : pycharm-community-2019.1.3

Conda : 4.7.5

typesetting : Markdown

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coder@ubuntu:~$ conda activate py37
(py37) coder@ubuntu:~$ ipython
Python 3.7.3 (default, Mar 27 2019, 22:11:17) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.5.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: my_str = "0123456789"                                                   

In [2]: "前三个字符", my_str[:3]                                                
Out[2]: ('前三个字符', '012')

In [3]: "后三个字符,倒序", my_str[-1:-4:-1]                                     
Out[3]: ('后三个字符,倒序', '987')

In [4]: "后三个字符,正序", my_str[-3:]                                          
Out[4]: ('后三个字符,正序', '789')

In [5]: start_index, end_index, step = 1, 7, 2                                  

In [6]: my_str[start_index: end_index: step]                                    
Out[6]: '135'

In [7]: # 反向提取                                                              

In [8]: # 字符串最后一个字符的索引也是 -1，倒数第二个字符的索引是-2             

In [9]: start_index, end_index, step = -1, -5, -1                               

In [10]: # -1 -2 -3 -4                                                          

In [11]: my_str[start_index: end_index: step]                                   
Out[11]: '9876'

In [12]: exit                                                                   
(py37) coder@ubuntu:~$ conda deactivate
coder@ubuntu:~$

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[文档 - English] docs.python.org/3
[文档 - 中文] docs.python.org/zh-cn/3
[规范] www.python.org/dev/peps/pep-0008
[规范] zh-google-styleguide.readthedocs.io/en/latest/google-python-styleguide/python_language_rules
[源码] www.python.org/downloads/source
[ PEP ] www.python.org/dev/peps
[平台] www.cnblogs.com
[平台] gitee.com

Python具有开源、跨平台、解释型、交互式等特性，值得学习。
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代码的书写要遵守规范，这样有助于沟通和理解。
每种语言都有独特的思想，初学者需要转变思维、踏实践行、坚持积累。

Python3基础 str : 对字符串进行切片

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