Building a Python environment on a Mac and using Jupyter lab

I stumbled upon building a Python environment on a Mac, so make a note.

To write from the conclusion first, the reason why it didn't work was because I was editing bash without knowing that MacOS became Catalina and the default shell changed from bash to zsh.

Until now, I was careful because I should have written the environment variables of pyenv to .bash_profile and .bashrc and sourced them.

It was said that technology is constantly updated, but if you do not update your knowledge, it may fail.

Then, I will describe what I actually did below.

1. Install Anaconda

https://www.anaconda.com/distribution/ From here, download python3.7 and unpack the package

When will Apply change the default python to 3 series?

2. Preparing to install python

Check the python version with $ python --version. If it is a mac, 2.7 is probably included as standard, so switch.

For that, put pyenv. So, in order to put pyenb, put Homebrew.

1. Install brew https://brew.sh/index_ja

2. Install pyenv with brew

   $ brew install pyenv
   

3. And here is where the problem stumbled.

   $ echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
   $ echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile
   $ echo 'eval "$(pyenv init -)"' >> ~/.bash_profile
   

Write the above in ~ / .zshrc. ← (When Mac OS is Catalina or higher) If the default shell is still bash, OS before Catalina, write to ~ / .bash_profile.

4. Execute $ source ~ / .zshrc or $ source ~ / .bash_profile

5. Check the environment variable PATH with $ echo $ PATH

   

3. Install python

This time, install 3.7.0. Please change the version to 3.7.4 etc. if necessary.

$ pyenv install 3.7.0

Is OK.

4. Switching python

$ python --version
Python 2.7.16

As it is still python2, switch to python3.

$ pyenv gloval 3.7.0
$ python --version
Python 3.7.0

Is OK! If this does not switch, restart the terminal once and try again.

5. Install anaconda

$ pyenv install anaconda3-5.3.1

I put the latest at this time. Check the version with $ pyenv install list.

6. Switch to anaconda

As it is, the conda command cannot be used, so switch to anaconda.

$ pyenv global anaconda3-5.3.1
$ pyenv versions              
  system
* 3.7.0 (set by /Users/User name/.python-version)
  anaconda3-5.3.1

That hasn't switched. Also, I stumbled here. The cause seems to be that the file .python-version exists here. So

$ rm ~/.python-version
$ pyenv versions
  system
  3.7.0
* anaconda3-5.3.1 (set by /Users/User name/.pyenv/version)

This completes the switch.

7. Start Jupyterlab

Recently, it seems that Jupyterlab is already installed in anaconda, so you don't have to bother to install it.

$ jupyter lab

Then it will start.