Python包? [英] Python Packages?

问题描述

好吧，我想无论我做错了什么，这可能都是显而易见的，但我无法弄清楚.我已经阅读并重新阅读了有关软件包的教程部分，我唯一能想到的是，这是行不通的，因为我直接执行了它.这是目录设置:

Ok, I think whatever I'm doing wrong, it's probably blindingly obvious, but I can't figure it out. I've read and re-read the tutorial section on packages and the only thing I can figure is that this won't work because I'm executing it directly. Here's the directory setup:

eulerproject/
  __init__.py
  euler1.py
  euler2.py
  ...
  eulern.py
  tests/
    __init__.py
    testeulern.py

这是testeuler12.py(我编写的第一个测试模块)的内容:

Here are the contents of testeuler12.py (the first test module I've written):

import unittest
from .. import euler12

class Euler12UnitTests(unittest.TestCase):


    def testtriangle(self):
        """
        Ensure that the triangle number generator returns the first 10
        triangle numbers.

        """
        self.seq = [1,3,6,10,15,21,28,36,45,55]
        self.generator = euler12.trianglegenerator()
        self.results = []
        while len(self.results) != 10:
            self.results.append(self.generator.next())
        self.assertEqual(self.seq, self.results)

    def testdivisors(self):
        """
        Ensure that the divisors function can properly factor the number 28.

        """
        self.number = 28
        self.answer = [1,2,4,7,14,28]
        self.assertEqual(self.answer, euler12.divisors(self.number))


if __name__ == '__main__':

    unittest.main()

现在，当我从目录中的IDLE和命令行执行此操作时，出现以下错误:

Now, when I execute this from IDLE and from the command line while in the directory, I get the following error:

Traceback (most recent call last):
  File "C:\Documents and Settings\jbennet\My Documents\Python\eulerproject\tests\testeuler12.py", line 2, in <module>
    from .. import euler12
ValueError: Attempted relative import in non-package

我认为问题在于，因为我直接运行它，所以我无法进行相对导入(因为__name__发生了变化，而我对软件包描述的含糊理解是，__name__是它说明方式的一部分

I think the problem is that since I'm running it directly, I can't do relative imports (because __name__ changes, and my vague understanding of the packages description is that __name__ is part of how it tells what package it's in), but in that case what do you guys suggest for how to import the 'production' code stored 1 level up from the test code?

推荐答案

通常，您会在PYTHONPATH上的某个位置找到一个目录，该目录的名称是您的软件包名称.例如:

Generally you would have a directory, the name of which is your package name, somewhere on your PYTHONPATH. For example:

eulerproject/
    euler/
        __init__.py
        euler1.py
        ...
        tests/
            ...
    setup.py

然后，您可以在系统范围内安装此版本，也可以确保在调用脚本时设置PYTHONPATH=/path/to/eulerproject/:$PYTHONPATH.

Then, you can either install this systemwide, or make sure to set PYTHONPATH=/path/to/eulerproject/:$PYTHONPATH when invoking your script.

这样的绝对导入将起作用:

An absolute import like this will then work:

from euler import euler1

编辑:

根据Python文档，打算用作Python应用程序主模块的模块应始终使用绝对导入." (引用)

According to the Python docs, "modules intended for use as the main module of a Python application should always use absolute imports." (Cite)

因此另一个答案提到的像nose这样的测试工具之所以起作用，是因为它导入软件包而不是从命令行运行它们.

So a test harness like nose, mentioned by the other answer, works because it imports packages rather than running them from the command line.

如果您想手动执行操作，则可运行脚本需要位于程序包层次结构之外，如下所示:

If you want to do things by hand, your runnable script needs to be outside the package hierarchy, like this:

eulerproject/
    runtests.py
    euler/
        __init__.py
        euler1.py
        ...
        tests/
            __init__.py
           testeulern.py

现在，runtests.py可以执行from euler.tests.testeulern import TestCase，testeulern.py可以执行from .. import euler1

Now, runtests.py can do from euler.tests.testeulern import TestCase and testeulern.py can do from .. import euler1

这篇关于Python包?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！