[Dynamic Language] Python非子包引用

Python非子包引用

python的搜索路径其实是一个列表(sys.path)
导入模块时python会自动去找搜索这个列表当中的路径，如果路径中存在要导入的模块文件则导入成功.

在项目中如果要引用同级包或另外目录的包(非子包)时:

1. 将引用包路径加入sys.path
2. 将引用包路径加入到*.pth文件内,并放入site.getsitepackages() 目录下.
3. 当然也可以打包发布，安装到python的特定目录下.

测试代码

查看Python搜索路径列表

In [1]: import sys                                                                                                                                                                

In [2]: sys.path                                                                                                                                                                  
Out[2]: 
['',
 '/Library/Frameworks/Python.framework/Versions/3.7/bin',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python37.zip',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/lib-dynload',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/IPython/extensions',]

代码目录

mac-abeen:page_pth_test abeen$ tree -L 3
├── dakjpka
│   ├── __init__.py
│   ├── pa
│   │   ├── __init__.py
│   │   ├── __pycache__
│   │   ├── pam.py
│   │   └── pam_rf.py
│   └── pb
│       └── pbm.py
└── tpackage.py

兄弟模块或者主运行程序与包同一级别或存在子包关系时

from package import module
import package

pam.py

   1 # -*- coding: utf-8 -*-                                                                                                                                                      
   2                                                                                 
   3                                                                                 
   4 def pam_fun():                                                                  
   5     print('p.pa pam_fun')                                                       
   6                                                                                 
   7                                                                                 
   8 __all__ = ['pam_fun']  

pam_rf.py

   1 # -*- coding: utf-8 -*-                                                                                                                                                      
   2                                                                                 
   3 from pam import pam_fun                                                         
   4                                                                                 
   5 if __name__ == "__main__":                                                      
  6     pam_fun() 

同级或另外的包引用

1. 直接添加到sys.path.append("package path")
2. 使用*.pth文件,放到python的特定目录下.

查看python特定目录

In [3]: import site                                                                                                                                                               

In [4]: site.getsitepackages()                                                                                                                                                    
Out[4]: ['/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages']

增加目录内容

mac-abeen:pa abeen$ cat /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/dakj_project.pth 
/Users/abeen/abeen/alearn/python/page_pth_test
/Users/abeen/abeen/ap/gitwork/dabda

增加后效果

In [5]: sys.path                                                                                                                                                                  
Out[5]: 
['',
 '/Library/Frameworks/Python.framework/Versions/3.7/bin',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python37.zip',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/lib-dynload',
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages',
**'/Users/abeen/abeen/alearn/python/page_pth_test',**
** '/Users/abeen/abeen/ap/gitwork/dabda',**
 '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/IPython/extensions',
 '/Users/abeen/.ipython']

pbm.py 引用pam.py内的pam_fun如下

   1 # -*- coding: utf-8 -*-                                                                                                                                                      
   2                                                                                 
   3 # from dakjpka.pa import pam                                                    
   4 import dakjpka.pa.pam as pam                                                    
   5                                                                                 
   6                                                                                 
   7 def pbm_fun():                                                                  
  8     print('p.pbm pbm_fun')                                                      
|  9     pam.pam_fun()                                                               
  10                                                                                 
  11                                                                                 
  12 if __name__ == '__main__':                                                      
 13     pbm_fun()                                                                   
  14                                                                                 
  15                                                                                 
  16 __all__ = ['pbm_fun'] 

run

mac-abeen:pb abeen$ python3 pbm.py 
p.pbm pbm_fun
p.pa pam_fun