Question

我正在尝试安装新模块，但我发现pip不起作用 - 它显示

pkg_resources.DistributionNotFound: The 'pip==1.5.6' distribution was not found and is required by the application

我执行的每个电话。另外，对于pip --help。我找到了一些建议，使用pip或pip重新安装easy_install，但easy_install也不起作用：

pkg_resources.DistributionNotFound: The 'setuptools==5.7' distribution was not found and is required by the application

有没有办法解决此问题而无需重新安装python及其所有模块？
我有Linux Ubuntu 14.04 apt-get install python-pip建议安装pip（以及一堆其他软件），就像我的系统中没有它一样。我害怕这样做，会在这里发生冲突吗？

UPD。
apt-get表示要安装以下内容：build-essential dpkg-dev fakeroot g++ g++-4.8 libalgorithm-diff-perl libalgorithm-diff-xs-perl libalgorithm-merge-perl libfakeroot libstdc++-4.8-dev python-chardet-whl python-colorama python-colorama-whl python-distlib python-distlib-whl python-html5lib python-html5lib-whl python-pip python-pip-whl python-requests-whl python-setuptools python-setuptools-whl python-six-whl python-urllib3-whl python-wheel。但据我所知，如果没有这些包裹，pip会为我工作我也表演了 which -a python：/usr/bin/python
which -a pip：/usr/local/bin/pip
python --version：Python 2.7.6

Answer 1

具有错误的完整回溯将很有用。可能导致此问题的一种情况是，安装了多个版本的Python。

例如，在我的Ubuntu 20.04.1 LTS上，除了从Ubuntu 20分发的Python 3.8之外，我还从源代码安装了Python 3.6。这是在安装Python 3.6之后使用pip3 --version的结果：

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 581, in _build_master
    ws.require(__requires__)
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 898, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 789, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.VersionConflict: (pip 20.2.3 (/usr/local/lib/python3.6/site-packages), Requirement.parse('pip==20.0.2'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/pip3", line 6, in <module>
    from pkg_resources import load_entry_point
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 3126, in <module>
    @_call_aside
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 3110, in _call_aside
    f(*args, **kwargs)
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 3139, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 583, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 596, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/local/lib/python3.6/site-packages/pkg_resources/__init__.py", line 784, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'pip==20.0.2' distribution was not found and is required by the application

最后一行是有问题的错误，但请注意回溯中的一个重要细节：raise VersionConflict。

可以通过explicitly using所需的pip版本来解决：

$ python3.6 -m pip --version
pip 20.2.3 from /usr/local/lib/python3.6/site-packages/pip (python 3.6)

或者简单地：

$ pip3.6 --version
pip 20.2.3 from /usr/local/lib/python3.6/site-packages/pip (python 3.6)

可能遇到的另一问题是在进行pip3.6 install时发生的missing lsb_release问题：

  File "/usr/local/lib/python3.6/subprocess.py", line 438, in run
    output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '('lsb_release', '-a')' returned non-zero exit status 1.

这可以通过找到lsb_release.py并创建一个符号链接来解决，例如：

sudo ln -s /usr/lib/python3/dist-packages/lsb_release.py /usr/local/lib/python3.6/site-packages/lsb_release.py

现在可以升级pip3.6并安装新软件包：

$ pip3.6 install --upgrade pip
$ pip3.6 install mypy

请注意，对于我发行版中的原始Python，我只使用pip3，而不是pip3.8。但是要使其正常工作，我需要先将当前的python切换到3.8。例如，我将执行sudo update-alternatives --config python并选择3.8。其他人可能对managing Python versions使用不同的方法。

当心更改系统的默认Python，它可能会引起问题，包括“终端未打开”之类的症状。最好有一个备用终端，例如Visual Studio Code中的一个。

python pip错误pkg_resources.DistributionNotFound

1 个答案: