import導入模塊

cli的目錄結構如下

?  cli tree
.
├── __pycache__
│   └── test.cpython-36.pyc
├── demo1
├── demo2
│   ├── __pycache__
│   │   └── test2.cpython-36.pyc
│   └── test2.py
└── test.py

若直接在test.py中import test2則會報以下錯誤

?  cli python3
Python 3.6.0 (default, Jan 23 2017, 14:53:49)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import test2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'test2'

通過以下方式查看import的搜索路徑

>>> import sys
>>> sys.path
[
'', 
'/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python36.zip', 
'/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6',
'/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3
]

所以可以將test2.Py的路徑加入上面的目錄的方式來解決

>>> sys.path
[
'', 
'/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python36.zip', 
'/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6',
'/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3，
'./demo2/'
]
// 重新導入后沒有再報錯
>>> import test2
>>> 
>>> 

由于此時的test2.py文件內(nèi)容為空

另開一個窗口編輯test2.py ,增加一個hello方法

15148114276369.jpg

回到左側調(diào)用hello方法會報以下錯誤

>>> import test2
>>> test2.hello()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'test2' has no attribute 'hello'

當然可以通過推出在重新導入的方式是可以的，另一種方式就是該篇的第二個話題：動態(tài)加載

動態(tài)加載模塊

場景：開了2個窗口同時編輯同一個文件，但又不想退出重進

>>> from imp import *
>>> reload(test2)
<module 'test2' from './demo2/test2.py'>

此時在調(diào)用hello方法即可

>>> test2.hello()
hello