add pyenv to python module

modules/python/README.md

@@ -16,6 +16,16 @@ execution of `pythonz`.
 
 Install Python versions with `pythonz install` into *~/.pythonz/pythons*.
 
+pyenv
+-----
+
+An alternative pythonz is to use [pyenv][6], which allows for switching between
+multiple, isolated Python installations in the home directory.
+
+### Usage
+
+Install Python versions with `pyenv install` into *~/.pyenv/versions*.
+
 Local Package Installation
 --------------------------
 
@@ -107,4 +117,4 @@ Authors
 [3]: http://pypi.python.org/pypi/virtualenv
 [4]: http://saghul.github.com/pythonz/
 [5]: https://github.com/sorin-ionescu/prezto/issues
-
+[6]: https://github.com/yyuu/pyenv

modules/python/init.zsh

@@ -9,10 +9,20 @@
 # Load pythonz into the shell session.
 if [[ -s $HOME/.pythonz/bin/pythonz ]]; then
   path=($HOME/.pythonz/bin $path)
+
+# Load manually installed pyenv into the shell session.
+elif [[ -s "$HOME/.pyenv/bin/pyenv" ]]; then
+  path=("$HOME/.pyenv/bin" $path)
+  eval "$(pyenv init -)"
+
+# Load package manager installed pyenv into the shell session.
+elif (( $+commands[pyenv] )); then
+  eval "$(pyenv init -)"
+
 fi
 
 # Return if requirements are not found.
-if (( ! $+commands[python] && ! $+commands[pythonz] )); then
+if (( ! $+commands[python] && ! ( $+commands[pythonz] || $+commands[pyenv] ) )); then
   return 1
 fi