最短最好的解决方案

conda create --name py3-ml python=3.6
conda install ipykernel

source activate py3-ml # or conda activate py3-ml
python -m ipykernel install --user --name py3-ml

我用以下命令成功地在macOS El Capitan (ipython版本:4.1.0)上安装了python3内核。

python3 -m pip install ipykernel
python3 -m ipykernel install --user

你可以在jupyter kernelspec列表中看到所有已安装的内核。

更多信息可以在这里找到

在Ubuntu 14.04上，我不得不使用之前答案的组合。

首先，安装pip3 安装python-pip3

然后用pip3安装jupyter Pip3安装jupyter

然后使用ipython3安装内核 Ipython3内核安装

确保已经安装了ipykernel，并使用ipython kernel install将kernelspec放到python2的正确位置。然后为Python3安装ipython3内核。现在，无论您使用的是jupyter notebook、ipython notebook还是ipython3 notebook(后两种已弃用)，您都应该能够在这两种内核之间进行选择。

注意，如果你想安装一个特定的Python可执行文件，你可以使用以下技巧:

path/to/python -m ipykernel install <options>

当使用环境(venv,conda，…)和<选项>让你命名你的内核时，这是有效的(参见——help)。所以你可以

conda create -n py36-test python=3.6
source activate py36-test
python -m ipykernel install --name py36-test
source deactivate

现在，在下拉菜单中可以看到名为py36-test的内核和其他内核。

参见使用Python 2。3. Python。IPython Notebook中的最新信息。

在ElementaryOS Freya(基于Ubuntu 14.04)上，其他答案都没有立即对我起作用;我得到了

[TerminalIPythonApp]警告|文件不存在:'kernelspec'

quickbug在Matt的回答中描述的错误。我首先要做的是:

Sudo apt-get安装pip3

安装ipython[所有]

这时你就可以运行Matt建议的命令了;即:ipython kernelspec install-self和ipython3 kernelspec install-self

现在，当我启动ipython notebook，然后打开一个notebook时，我能够从kernel菜单中选择Python 3内核。

将多个内核安装到单个虚拟环境(venv)

这些答案中的大多数(如果不是全部的话)假设您乐于在全局范围内安装包。这个答案适合你，如果你:

使用*NIX机器 不喜欢全局安装包 不要使用anaconda <->，你很乐意从命令行运行jupyter服务器 想要知道内核安装“在哪里”。

(注意:这个答案在python3-jupyter安装中添加了一个python2内核，但在概念上很容易交换。)

Prerequisites You're in the dir from which you'll run the jupyter server and save files python2 is installed on your machine python3 is installed on your machine virtualenv is installed on your machine Create a python3 venv and install jupyter Create a fresh python3 venv: python3 -m venv .venv Activate the venv: . .venv/bin/activate Install jupyterlab: pip install jupyterlab. This will create locally all the essential infrastructure for running notebooks. Note: by installing jupyterlab here, you also generate default 'kernel specs' (see below) in $PWD/.venv/share/jupyter/kernels/python3/. If you want to install and run jupyter elsewhere, and only use this venv for organizing all your kernels, then you only need: pip install ipykernel You can now run jupyter lab with jupyter lab (and go to your browser to the url displayed in the console). So far, you'll only see one kernel option called 'Python 3'. (This name is determined by the display_name entry in your kernel.json file.) Add a python2 kernel Quit jupyter (or start another shell in the same dir): ctrl-c Deactivate your python3 venv: deactivate Create a new venv in the same dir for python2: virtualenv -p python2 .venv2 Activate your python2 venv: . .venv2/bin/activate Install the ipykernel module: pip install ipykernel. This will also generate default kernel specs for this python2 venv in .venv2/share/jupyter/kernels/python2 Export these kernel specs to your python3 venv: python -m ipykernel install --prefix=$PWD/.venv. This basically just copies the dir $PWD/.venv2/share/jupyter/kernels/python2 to $PWD/.venv/share/jupyter/kernels/ Switch back to your python3 venv and/or rerun/re-examine your jupyter server: deactivate; . .venv/bin/activate; jupyter lab. If all went well, you'll see a Python 2 option in your list of kernels. You can test that they're running real python2/python3 interpreters by their handling of a simple print 'Hellow world' vs print('Hellow world') command. Note: you don't need to create a separate venv for python2 if you're happy to install ipykernel and reference the python2-kernel specs from a global space, but I prefer having all of my dependencies in one local dir

博士TL;

Optionally install an R kernel. This is instructive to develop a sense of what a kernel 'is'. From the same dir, install the R IRkernel package: R -e "install.packages('IRkernel',repos='https://cran.mtu.edu/')". (This will install to your standard R-packages location; for home-brewed-installed R on a Mac, this will look like /usr/local/Cellar/r/3.5.2_2/lib/R/library/IRkernel.) The IRkernel package comes with a function to export its kernel specs, so run: R -e "IRkernel::installspec(prefix=paste(getwd(),'/.venv',sep=''))". If you now look in $PWD/.venv/share/jupyter/kernels/ you'll find an ir directory with kernel.json file that looks something like this:

{
  "argv": ["/usr/local/Cellar/r/3.5.2_2/lib/R/bin/R", "--slave", "-e", "IRkernel::main()", "--args", "{connection_file}"],
  "display_name": "R",
  "language": "R"
}

总之，内核只是从内核调用特定于语言的可执行文件。Json文件，jupyter在…/share/jupyter/kernels目录和列表在本例中，调用R来运行IRkernel::main()函数，该函数将向Jupiter服务器来回发送消息。类似地，python2内核只是使用ipykernel_launcher模块调用python2解释器，如.venv/share/jupyter/kernels/python2/kernel中所示。json等。

如果您想一下子运行所有这些指令，这里有一个脚本。