在 src 布局中使用 attr 时出现 ModuleNotFoundError

ModuleNotFoundError when using attr with the src layout

我正在使用 setuptools 开发一个 Python 包。我使用 src 布局使用 setup.cfg file 设置配置。在 Travis-CI 的 Python 3.6 上,我得到一个 ModuleNotFoundError.

src 布局给出了以下结构:

my-package
├── setup.cfg
├── setup.py
└── src
    └── my_package
        ├── my_file.py
        └── version.py

如文档中所述,我使用 attr: 说明符获取版本。我还使用 extras_require 键来获取一些额外的依赖项 (especially for having test tool executables)。

[metadata]
name = mypackage
version = attr: my_package.version.__version__

[options]
package_dir =
        =src
packages = find:

[options.packages.find]
where = src

[options.extras_require]
test =
        dummy

然后,我使用pip安装依赖:

pip install -e ".[test]"

这在使用 Python 3.7 的本地环境和使用 Python 3.5 的 Travis-CI 环境中无缝工作。但是在使用 Python 3.6 的 Travis-CI 环境中,我得到一个 ModuleNotFoundError:

Obtaining file:///home/travis/build/me/my-package
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/home/travis/build/me/my-package/setup.py", line 4, in <module>
        setup()
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/__init__.py", line 129, in setup
        return distutils.core.setup(**attrs)
      File "/opt/python/3.6.3/lib/python3.6/distutils/core.py", line 121, in setup
        dist.parse_config_files()
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/dist.py", line 436, in parse_config_files
        ignore_option_errors=ignore_option_errors)
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/config.py", line 106, in parse_configuration
        meta.parse()
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/config.py", line 382, in parse
        section_parser_method(section_options)
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/config.py", line 355, in parse_section
        self[name] = value
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/config.py", line 173, in __setitem__
        value = parser(value)
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/config.py", line 428, in _parse_version
        version = self._parse_attr(value)
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/setuptools/config.py", line 305, in _parse_attr
        module = import_module(module_name)
      File "/home/travis/virtualenv/python3.6.3/lib/python3.6/importlib/__init__.py", line 126, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
      File "<frozen importlib._bootstrap>", line 994, in _gcd_import
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 941, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
      File "<frozen importlib._bootstrap>", line 994, in _gcd_import
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked
    ModuleNotFoundError: No module named 'my_package'

怎么了?

Travis-CI 为 Python 3.6 提供的 setuptools 包似乎太旧,无法正确使用 attr: 说明符。这个特性可以使用in v39.2.0,而Travis-CI Python 3.6提供v38.2.4(因此报错),Travis-CI Python 3.5提供40.0.0(因此成功了)。

所以,我只是输入:

pip install --upgrade "setuptools>=40.0"

作为我的 .travis-ci.yaml 文件中的先决条件。

我在使用 setuptools 46.x 时遇到了同样的错误,但我的 setup.cfg 略有不同。这部分很重要:

[options]
package_dir =
        =src
packages = find:

[options.packages.find]
where = src