How do I change the python shell version using pyenv?

hoodedvul

Also see:
pyenv help
How do I install the python multiple version management tool pyenv?

Version of the shell before the change.

$ python
Python 3.8.5 (default, Oct  8 2020, 13:36:54)
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> quit()

Check the versions available.

$ pyenv versions
  system
  2.7.15
  3.8.5
* 3.8-dev (set by /home/trainer/demo_env/.python-version)

Change the python shell to version 2.7.15

$ pyenv shell 2.7.15

Run python again. You can see it is now 2.7.15

$ python
Python 2.7.15 (default, Oct  8 2020, 14:02:01)
[GCC 9.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>

Note: The shell command overrides local and global commands.

To unset the shell use the --unset option.

$ pyenv shell 3.8.5 --unset