Python3基礎 str : 對字符串進行切片

 

•        Python : 3.7.3
•          OS : Ubuntu 18.04.2 LTS
•         IDE : pycharm-community-2019.1.3
•       Conda : 4.7.5
•    typesetting : Markdown

 

code

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]: "前三個字符", my_str[:3]                                                
Out[2]: ('前三個字符', '012')

In [3]: "後三個字符,倒序", my_str[-1:-4:-1]                                     
Out[3]: ('後三個字符,倒序', '987')

In [4]: "後三個字符,正序", my_str[-3:]                                          
Out[4]: ('後三個字符,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]: # 字符串最後一個字符的索引也是 -1，倒數第二個字符的索引是-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:~$

 

resource

• [文檔 - English] docs.python.org/3
• [文檔 - 中文] docs.python.org/zh-cn/3
• [規範] www.python.org/dev/peps/pep-0008
• [規範] zh-google-styleguide.readthedocs.io/en/latest/google-python-styleguide/python_language_rules
• [源碼] www.python.org/downloads/source
• [ PEP ] www.python.org/dev/peps
• [平臺] www.cnblogs.com
• [平臺] gitee.com

 

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Python具備開源、跨平臺、解釋型、交互式等特性，值得學習。
Python的設計哲學：優雅，明確，簡單。提倡用一種方法，最好是隻有一種方法來作一件事。
代碼的書寫要遵照規範，這樣有助於溝通和理解。
每種語言都有獨特的思想，初學者須要轉變思惟、踏實踐行、堅持積累。