WARNING:param.extension: Holoviews bokeh extension could not be imported, it raised the fo

Question

WARNING:param.extension: Holoviews bokeh extension could not be imported, it raised the following exception: RuntimeError('There is no current event loop in thread 'Dummy-1'.')
Exception ignored in thread started by: <function check_errors..wrapper at 0x000001F53E96FA60>
Traceback (most recent call last):
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\utils\autoreload.py", line 225, in wrapper
fn(*args, **kwargs)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\core\management\commands\runserver.py", line 120, in inner_run
self.check(display_num_errors=True)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\core\management\base.py", line 361, in check
all_issues = self._run_checks(
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\core\management\base.py", line 351, in run_checks
return checks.run_checks(**kwargs)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\core\checks\registry.py", line 73, in run_checks
new_errors = check(app_configs=app_configs)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\core\checks\urls.py", line 13, in check_url_config
return check_resolver(resolver)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\core\checks\urls.py", line 23, in check_resolver
return check_method()
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\urls\resolvers.py", line 397, in check
for pattern in self.url_patterns:
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\utils\functional.py", line 36, in get
res = instance.dict[self.name] = self.func(instance)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\urls\resolvers.py", line 536, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\utils\functional.py", line 36, in get
res = instance.dict[self.name] = self.func(instance)
File "C:\Users\57797\AppData\Roaming\Python\Python39\site-packages\django\urls\resolvers.py", line 529, in urlconf_module
return import_module(self.urlconf_name)
File "C:\Program Files\Python39\lib\importlib_init.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1030, in _gcd_import
File "", line 1007, in _find_and_load
File "", line 986, in _find_and_load_unlocked
File "", line 680, in load_unlocked
File "", line 850, in exec_module
File "", line 228, in call_with_frames_removed
File "C:\Users\57797\PycharmProjects\HealthRecommandSystem\HealthRecommandSystem\urls.py", line 19, in
from health import views
File "C:\Users\57797\PycharmProjects\HealthRecommandSystem\health\views.py", line 188, in
from myhealth import initMethod, recipe_recommend, female_japanese_each, method
File "C:\Users\57797\PycharmProjects\HealthRecommandSystem\myhealth.py", line 11, in
hv.extension('bokeh')
File "C:\Users\57797\PycharmProjects\HealthRecommandSystem\venv\lib\site-packages\pyviz_comms_init.py", line 64, in new
return param.ParameterizedFunction.new(cls, *args, **kwargs)
File "C:\Users\57797\PycharmProjects\HealthRecommandSystem\venv\lib\site-packages\param\parameterized.py", line 4428, in new
return inst.call(*args,**params)
File "C:\Users\57797\PycharmProjects\HealthRecommandSystem\venv\lib\site-packages\holoviews\util_init.py", line 716, in call
raise ImportError('None of the backends could be imported')
ImportError: None of the backends could be imported

Answer 1

从你的错误堆栈可以看出，代码在运行时出现了问题，无法导入 holoviews 所需要的 bokeh 后端。以下是解决此问题的一些可选方法：

安装 bokeh包。
在你的环境中可能缺少 bokeh，你可以使用pip或conda安装它：

pip install bokeh

或

conda install bokeh

确保 bokeh 版本与 holoviews 兼容。
有时，不同版本的软件包可能不兼容。你应该确保你正在使用的 bokeh 版本与 holoviews 兼容。
检查你的环境变量。
错误可能是因为Python在搜索这些库文件时没有在正确的位置查找。确保Python解释器知道在哪里找到你的库。
在代码中直接导入 bokeh ：
尝试在引用 holoviews 之前导入 bokeh：

import bokeh

运行你的代码在新的虚拟环境中：
有时候，问题可能是由于环境中的某些包有冲突。你可以试试创建一个新的虚拟环境，并在那里只安装你需要的包。

以上步骤应该能够帮助你解决这个问题。如果问题依然存在，我建议从更深层次的环境或系统配置中查找问题，或者考虑寻找专业的帮助。