ImportError：没有名为 dash 的模块

Question

我无法在生产服务器中安装 dash。在本地，我通过

导入

pip install dash==0.29.0

但在 prod 中它不起作用。当我使用

sudo apt-get install python dash

它的显示

> "dash is already the newest version (0.5.8-2.4)"

，但是在使用 import dash 时，我得到了

> "ImportError: No module named dash"

也试过了

sudo pip install python dash==0.29.0

但它给出了以下错误：

Requirement already satisfied: python in /usr/lib/python2.7/lib-dynload
Collecting dash==0.29.0
Exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 353, in run
    wb.build(autobuilding=True)
  File "/usr/lib/python2.7/dist-packages/pip/wheel.py", line 749, in build
    self.requirement_set.prepare_files(self.finder)
  File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 380, in prepare_files
    ignore_dependencies=self.ignore_dependencies))
  File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 554, in _prepare_file
    require_hashes
  File "/usr/lib/python2.7/dist-packages/pip/req/req_install.py", line 278, in populate_link
    self.link = finder.find_requirement(self, upgrade)
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 465, in find_requirement
    all_candidates = self.find_all_candidates(req.name)
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 423, in find_all_candidates
    for page in self._get_pages(url_locations, project_name):
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 568, in _get_pages
    page = self._get_page(location)
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 683, in _get_page
    return HTMLPage.get_page(link, session=self.session)
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 792, in get_page
    "Cache-Control": "max-age=600",
  File "/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/sessions.py", line 501, in get
    return self.request('GET', url, **kwargs)
  File "/usr/lib/python2.7/dist-packages/pip/download.py", line 386, in request
    return super(PipSession, self).request(method, url, *args, **kwargs)
  File "/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/sessions.py", line 488, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/sessions.py", line 609, in send
    r = adapter.send(request, **kwargs)
  File "/usr/share/python-wheels/CacheControl-0.11.7-py2.py3-none-any.whl/cachecontrol/adapter.py", line 47, in send
    resp = super(CacheControlAdapter, self).send(request, **kw)
  File "/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/adapters.py", line 423, in send
    timeout=timeout
  File "/usr/share/python-wheels/urllib3-1.19.1-py2.py3-none-any.whl/urllib3/connectionpool.py", line 643, in urlopen
    _stacktrace=sys.exc_info()[2])
  File "/usr/share/python-wheels/urllib3-1.19.1-py2.py3-none-any.whl/urllib3/util/retry.py", line 315, in increment
    total -= 1
TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'

Answer 1

命令sudo apt-get install python dash 安装system 包python（正确）和system 包dash（不正确），即linux shell。

用sudo apt-get install python安装Python后，要安装python package dash，你需要做sudo pip install dash==0.29.0或sudo python -m pip install dash==0.29.0。

Answer 2

据我所知——而且我非常环保——似乎 python/environments 在适当的“站点包”目录中按文件名扫描模块。我已经通过命令提示符为我的系统 python 安装了 Dash，然后还通过 anaconda 命令提示符安装了 Dash。

当我尝试通过 anaconda 在 Spyder 中导入 dash 时，我遇到了同样的错误。我能够通过将包含 init 文件的文件夹从 dash_rendered 重命名为 just dash 来解决此问题。

看起来，当 Spyder 扫描它的包时，它可以识别正确的目录。

使用 Plotly 在命令行中提供的命令，我通常可以轻松地将 dash 安装到 python。

pip install dash==1.7.0

我可以看到这是一年前的事情，从那时起 Dash 发生了一些变化 - 但希望这可以帮助未来的用户，因为他们的环境在没有重命名的情况下无法将模块识别为“dash”，就像在 Spyder 中一样。

Answer 3

我遇到了同样的问题，我在 conda 终端上运行 pip install dash 解决了它（如果您使用的是 Anaconda）。

Answer 4

创建虚拟环境：

virtualenv venv # creates a virtualenv called "venv"
source venv/bin/activate # uses the virtualenv

然后pip install dash

Answer 5

如果您使用的是 Jupyter notebook 或 Jupyter Lab，请尝试install jupyter-dash by：

pip install jupyter-dash

在代码中：

from jupyter_dash import JupyterDash

pd.options.plotting.backend = "plotly"

Answer 6

file>NewProjectsSetup>Preferencesfornewprojects>PythonInterpreter> 点击+号搜索包，搜索破折号，安装包就可以了。