对我来说，在激活虚拟环境之前，它不起作用。

尝试“pip3 install jupyter”，而不是pip。这对我很管用。

以下是我在Linux mint 19上所做的:

我安装jupyter与:

pip install jupyter

和命令:

jupyter notebook

没有工作，所以:

sudo apt install jupyter-notebook

我解决了这个问题，jupyter笔记本工作了。

安装 jupyterlab。

如果你得到这个错误:

ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts.

We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default.

requests 2.25.1 requires idna<3,>=2.5, but you'll have idna 3.1 which is incompatible.

用这个:

pip3 install jupyterlab --use-feature=2020-resolver

大多数情况下(在jupyter不在/local/bin的情况下)使用，

which jupyter

示例输出

~/miniconda3/bin/jupyter

要查看jupyter的路径，请使用sudo显式地使用该路径

sudo ~/miniconda3/bin/jupyter 

在Mac OS上，您需要导出~/。在$PATH变量中使用local/bin。

# Edit the bash profile:
$ vim ~/.bash_profile

# Add this line inside ~/.bash_profile:
export PATH=$PATH:~/.local/bin

# Update the source:
$ source ~/.bash_profile

# Open Jupyter:
$ jupyter notebook