python3：导入错误：没有名为 xxxx 的模块
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/34461987/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
python3: ImportError: No module named xxxx
提问by MatrixClient
I am new to Python and I am trying to understand a problem, which I see when creating a package. I have the following file structure: (Working-Directory is /my/Python/jmLib2)
我是 Python 新手，我试图理解一个问题，我在创建包时看到了这个问题。我有以下文件结构：（工作目录是/my/Python/jmLib2）
/my/Python/jmLib2
|--- Phone
| |--- __init__.py
| |--- Pots.py
|- Test2.py
---------------------------------
cat ./jmLib2/Pots.py
#!/usr/bin/python
def Pots():
print ("I'm Pots Phone")
---------------------------------
cat ./jmLib2/__init__.py
from Pots import Pots
---------------------------------
cat ./Test2.py
#!/usr/bin/python
from Phone import Pots
import os.path
print ("OS:"+str(os.path))
Pots()
When I now do:
当我现在做：
python2 Test2.py
OS:<module 'posixpath' from '/usr/lib/python2.7/posixpath.pyc'>
I'm Pots Phone*
GREAT...BUT, if I do:
很好……但是，如果我这样做：
python3 Test2.py
Traceback (most recent call last):
File "Test2.py", line 2, in <module>
from Phone import Pots
File "/home/juergen/my/Python/jmLib2/Phone/__init__.py", line 1, in <module>
from Pots import Pots
ImportError: No module named 'Pots'
I am working with PyDev under Eclipse. PyDev reports me inside the init.py file an "Unresolved import: Pots"-error. I have the same traceback-problem under PyDev and bash.
我正在 Eclipse 下使用 PyDev。PyDev 在init.py 文件中向我报告“未解析的导入：Pots”错误。我在 PyDev 和 bash 下有相同的回溯问题。
Again, I am new to Python... so it is maybe a very stupid mistake. But can someone explain me, the difference between python2 and python3.4? Do I have to modify the PYTHONPATH? Why?
同样，我是 Python 的新手……所以这可能是一个非常愚蠢的错误。但是有人可以解释一下，python2 和 python3.4 之间的区别吗？我必须修改 PYTHONPATH 吗？为什么？
Greetings Juergen
问候尤尔根
采纳答案by Andrea Corbellini
TL;DR:Relative imports are gone. Use absolute imports instead.
TL;DR：相对进口消失了。请改用绝对导入。
Either use:
要么使用：
from Phone.Pots import Pots
or:
或者：
from .Pots import Pots
The problem occurs because Potsis part of the Phonepackage: there is no module named Pots, there's a module named Phone.Pots.
出现问题是因为Pots是Phone包的一部分：没有名为 的模块Pots，有一个名为 的模块Phone.Pots。
Python 2 had a feature called relative importsthat let you write import Potseven if that was not technically correct.
Python 2 有一个称为相对导入的功能，import Pots即使这在技术上不正确，也可以让您编写。
Relative imports however are a source of problems and confusion:
然而，相对进口是问题和混乱的根源：
- Who reads the code cannot immediately say whether the import is from a package or not.
- How come the module is named
Phone.Pots, but I can useimport Pots? This is highly inconsistent. - What if the submodule shadows a name of another module?
- 阅读代码的人无法立即说出导入是否来自包。
- 为什么模块被命名
Phone.Pots，但我可以使用import Pots？这是非常不一致的。 - 如果子模块隐藏了另一个模块的名称怎么办？
For these reasons, relative imports were removed from Python 3.
由于这些原因，从 Python 3 中删除了相对导入。
You can get rid of relative imports from Python 2 by using a __future__import:
您可以使用__future__import摆脱 Python 2 的相对导入：
from __future__ import absolute_import
