选项卡上的 Jupyter 自动完成/建议不起作用

Question

在使用像 nltk 这样的库时，选项卡自动完成就像一种祝福，它可以轻松地列出正在使用的模块的功能和属性。 几个月前它曾经工作得很好，但最近我一直面临这个自动完成没有出现的新问题。 它们最初似乎工作正常，但一段时间后，内核活动指示器只是在按下 Tab 键时闪烁，而没有任何反应。 在 jupyter 服务器端，出现以下消息：

[IPKernelApp] ERROR | Exception in message handler:
Traceback (most recent call last):
  File "<the path>\venv\lib\site-packages\ipykernel\kernelbase.py", line 268, in dispatch_shell
    yield gen.maybe_future(handler(stream, idents, msg))
  File "<the path>\venv\lib\site-packages\tornado\gen.py", line 735, in run
    value = future.result()
  File "<the path>\venv\lib\site-packages\tornado\gen.py", line 209, in wrapper
    yielded = next(result)
  File "<the path>\venv\lib\site-packages\ipykernel\kernelbase.py", line 583, in complete_request
    matches = yield gen.maybe_future(self.do_complete(code, cursor_pos))
  File "<the path>\venv\lib\site-packages\ipykernel\ipkernel.py", line 360, in do_complete
    return self._experimental_do_complete(code, cursor_pos)
  File "<the path>\venv\lib\site-packages\ipykernel\ipkernel.py", line 385, in _experimental_do_complete
    completions = list(_rectify_completions(code, raw_completions))
  File "<the path>\venv\lib\site-packages\IPython\core\completer.py", line 484, in rectify_completions
    completions = list(completions)
  File "<the path>\venv\lib\site-packages\IPython\core\completer.py", line 1819, in completions
    if c and (c in seen):
  File "<the path>\venv\lib\site-packages\IPython\core\completer.py", line 1876, in _completions
    else:
  File "<the path>\venv\lib\site-packages\IPython\core\completer.py", line 991, in _make_signature
    return '(%s)'% ', '.join([f for f in (_formatparamchildren(p) for p in completion.params) if f])
  File "<the path>\venv\lib\site-packages\IPython\core\completer.py", line 991, in <listcomp>
    return '(%s)'% ', '.join([f for f in (_formatparamchildren(p) for p in completion.params) if f])
  File "<the path>\venv\lib\site-packages\IPython\core\completer.py", line 991, in <genexpr>
    return '(%s)'% ', '.join([f for f in (_formatparamchildren(p) for p in completion.params) if f])
  File "<the path>\venv\lib\site-packages\IPython\core\completer.py", line 968, in _formatparamchildren
    raise ValueError('Jedi function parameter description have change format.'
ValueError: Jedi function parameter description have change format.Expected "param ...", found 'def __subclasshook__'".

虽然这不会严重阻碍开发过程，但如果它工作正常，它会非常有帮助。

我目前正在使用 python 3.8.6 64 位（在旧版本上也面临同样的问题）并在 Microsoft Edge Chromium 中运行笔记本

Answer 1

绝地是这里的问题。

你可以通过 jupyter 魔法解决这个问题。 只需在笔记本顶部添加以下内容：

%config Completer.use_jedi = False

另一种处理方法是删除系统上的绝地缓存（ https://github.com/ipython/ipython/issues/12134#issuecomment-590952054 ）：

您需要清除绝地缓存：只需删除文件夹（linux）

~/.cache/jedi/

你应该没事的。

对于其他操作系统，请检查

https://jedi.readthedocs.io/en/latest/docs/settings.html#filesystem-cache