在 jupyterlab 和 jupyter notebook 中集成conda虛擬環境

在jupyterlab中切換虛擬環境使用jupyter-conda包，參考鏈接：https://pypi.org/project/jupyter-conda/

Install
Requirements

conda >= 4.5
notebook >= 4.3
JupyterLab 1.0 (for the jupyterlab extension only)

To install in the classical notebook:

conda install -c conda-forge jupyter_conda

To install in the JupyterLab:

conda install -c conda-forge jupyterlab jupyter_conda
jupyter labextension install jupyterlab_toastify jupyterlab_conda

之前采用的是nb_conda_kernels包，該包在jupyter notebook中運行良好，但在jupyterlab中失效，切換虛擬環境運行無效。

jupyter-conda包是nb_conda_kernels包的分支，這是官網的解釋：
Provides Conda environment and package access extension from within Jupyter Notebook and JupyterLab.
This is a fork of the Anaconda nb_conda package. The decision to fork it came due to apparently dead status of the previous package and a need to integrate it within JupyterLab.