Configure Python develop tool chain

- use pyenv to manage the develop environments
  + install several Python versions (3.7 - 3.10 and 2.7)
  + each version receives its own copies of black, pipenv, and poetry
- add two more virtual environments based off the latest version:
  + "interactive" => default environment optimized for interactive
                     usage with with black, bpython, and ipython
                     (also receives accidental `pip install`s)
  + "utils" => hosts various globally available tools/apps
               (e.g., mackup and youtube-dl)
- add installation and update scripts for the entire tool chain
- set up completions for bash and zsh
- set up convenient aliases
- configure bpython
- configure poetry

.config/shell/aliases.sh

@@ -86,6 +86,25 @@ alias more='less'
 alias tree='tree -C --dirsfirst'
 
 
+# Make working with Python more convenient
+
+# Interactive shells
+alias py='python'
+alias bpy='bpython'
+alias ipy='ipython'
+
+if _command_exists poetry; then
+    alias pr='poetry run'
+fi
+
+if _command_exists pyenv; then
+    alias pyvenvs='pyenv virtualenvs --bare --skip-aliases'
+    alias pyver='pyenv version'
+    alias pyvers='pyenv versions --skip-aliases'
+    alias pywhich='pyenv which'
+fi
+
+
 # Various one-line utilities
 alias datetime='date +"%Y-%m-%d %H:%M:%S %z (%Z)"'
 alias datetime-iso='date --iso-8601=seconds'