2

我很好奇下面的情况。假设我有两个名为project_alphaand的项目project_bravo，它们都定义了一个顶级命名空间包mymeta。布局：

project_alpha/
   -> mymeta/
        -> __init__.py
        -> project_alpha/
             -> __init__.py
             -> version.py
   -> setup.py

project_bravo/
   -> mymeta/
        -> __init__.py
        -> project_bravo/
             -> __init__.py
             -> version.py
   -> setup.py

两个mymeta/__init__.pys 仅包含该行__import__('pkg_resources').declare_namespace(__name__)（根据setuptools 文档中的命名空间部分）。两个version.pys的内容： 

__version_info__ = (0, 9, 9, 'dev0')
__version__ = '.'.join((str(entry) for entry in __version_info__))

的setup.py脚本project_alpha非常简单。命名空间包mymeta被声明，版本取自version模块： 

# project_alpha
from setuptools import find_packages, setup
from mymeta.project_alpha.version import __version__

setup(
    name='mymeta.project-alpha',
    version=__version__,
    namespace_packages=['mymeta'],
    packages=find_packages(),
)

的setup.py脚本project_bravo具有相同的结构，但有一点不同：project_bravo取决于project_alpha构建时间： 

from setuptools import find_packages, setup
from mymeta.project_bravo.version import __version__

setup(
    name='mymeta.project-bravo',
    version=__version__,
    namespace_packages=['mymeta'],
    setup_requires=['mymeta.project-alpha'],
    packages=find_packages(),
)

构建时project_bravo，我收到以下错误：

~/project_bravo $ python setup.py sdist 
Traceback (most recent call last):
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 156, in save_modules
    yield saved
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 197, in setup_context
    yield
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 246, in run_setup
    DirectorySandbox(setup_dir).run(runner)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 276, in run
    return func()
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 245, in runner
    _execfile(setup_script, ns)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 47, in _execfile
    exec(code, globals, locals)
  File "/tmp/easy_install-ahmxos98/mymeta.project-alpha-0.9.9.dev0/setup.py", line 6, in <module>
    try:
ImportError: No module named 'mymeta.project_alpha'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "setup.py", line 22, in <module>
    packages=find_packages(),
  File "/usr/lib64/python3.5/distutils/core.py", line 108, in setup
    _setup_distribution = dist = klass(attrs)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/dist.py", line 315, in __init__
    self.fetch_build_eggs(attrs['setup_requires'])
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/dist.py", line 361, in fetch_build_eggs
    replace_conflicting=True,
  File "/tmp/tstenv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 853, in resolve
    dist = best[req.key] = env.best_match(req, ws, installer)
  File "/tmp/tstenv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 1125, in best_match
    return self.obtain(req, installer)
  File "/tmp/tstenv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 1137, in obtain
    return installer(requirement)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/dist.py", line 429, in fetch_build_egg
    return cmd.easy_install(req)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/command/easy_install.py", line 665, in easy_install
    return self.install_item(spec, dist.location, tmpdir, deps)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/command/easy_install.py", line 695, in install_item
    dists = self.install_eggs(spec, download, tmpdir)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/command/easy_install.py", line 876, in install_eggs
    return self.build_and_install(setup_script, setup_base)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/command/easy_install.py", line 1115, in build_and_install
    self.run_setup(setup_script, setup_base, args)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/command/easy_install.py", line 1101, in run_setup
    run_setup(setup_script, args)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 249, in run_setup
    raise
  File "/usr/lib64/python3.5/contextlib.py", line 77, in __exit__
    self.gen.throw(type, value, traceback)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 197, in setup_context
    yield
  File "/usr/lib64/python3.5/contextlib.py", line 77, in __exit__
    self.gen.throw(type, value, traceback)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 168, in save_modules
    saved_exc.resume()
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 143, in resume
    six.reraise(type, exc, self._tb)
  File "/tmp/tstenv/lib/python3.5/site-packages/pkg_resources/_vendor/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 156, in save_modules
    yield saved
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 197, in setup_context
    yield
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 246, in run_setup
    DirectorySandbox(setup_dir).run(runner)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 276, in run
    return func()
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 245, in runner
    _execfile(setup_script, ns)
  File "/tmp/tstenv/lib/python3.5/site-packages/setuptools/sandbox.py", line 47, in _execfile
    exec(code, globals, locals)
  File "/tmp/easy_install-ahmxos98/mymeta.project-alpha-0.9.9.dev0/setup.py", line 6, in <module>
    try:
ImportError: No module named 'mymeta.project_alpha'

不幸的是，我不明白这里的错误。跟进口订单有关系吧？如果我注释掉mymeta.project_bravo.versionin的导入project_bravo/setup.py并version用一些硬编码的字符串替换，突然构建成功......

编辑：我为这个问题介绍了一个解决方法。我没有尝试直接导入版本，而是exec使用版本模块来避免导入问题。当然，这不是一个正确的解决方案，因此没有将其发布为答案，但仍然在这里： 

__version__ = None # if the exec fails, leave the version unset, the resulting build version will be 0.0.0
version_script_path = os.path.relpath(os.path.join(os.path.dirname(__file__), 'mymeta', 'project_alpha', 'version.py'))
with open(version_script_path) as version_script:
    exec(version_script.read())

读取并执行版本脚本后，版本被初始化，因此无需从mymeta包中导入任何内容。

4

2 回答 2

2

差不多一年后，我再次面临这个问题，解决方案是使用PEP 420python>=3.3中指定的隐式命名空间包。项目结构几乎没有改变，只是pkgutil-style 命名空间包的 s都没有了：__init__.pymymeta

project_alpha/
   -> mymeta/
        -> project_alpha/
             -> __init__.py
             -> version.py
   -> setup.py

project_bravo/
   -> mymeta/
        -> project_bravo/
             -> __init__.py
             -> version.py
   -> setup.py

为了setuptools开心，两个设置脚本也需要调整：

...
setup(
    ...
    packages=['mymeta.' + pkg for pkg in find_packages('mymeta')],
)

现在导入将在构建时正确解析project-bravo。

于 2017-07-21T23:00:58.097 回答
1

如评论中所述：命令

$ python setup.py sdist

用于从私人 pypi 存储库mymeta.project_bravo下载鸡蛋。mymeta.project_alpha

命名空间包对它们的导入非常敏感。

例如，我发现当我在我的环境中定期安装ns.a并在 site-packages 目录中的 .pth 文件中ns.b提供导入路径时ns.d，无论如何它都不起作用。但是，当我ns.d在 site-packeges/ns 目录中进行符号链接时，它将起作用。

如果我不安装任何组件并在站点包目录中的 .pth 中提供所有路径，则一切正常。

如果我定期安装所有组件，一切正常。

就在我混合概念时，它不起作用。

因此我怀疑这也可能是这里的问题：导入路径的不同策略。

您可能想尝试将__init__.py文件修改为：

from pkgutil import extend_path

__path__ = extend_path(__path__, __name__)
__import__('pkg_resources').declare_namespace(__name__)

我很遗憾我决定做命名空间包。我再也不会这样做了。

于 2016-09-30T13:29:53.733 回答