python: remove zstyle setting in favor of third party environment variable

Refs #1519, #1520

modules/python/README.md

@@ -114,14 +114,6 @@ zstyle ':prezto:module:python:virtualenv' auto-switch 'yes'
 zstyle ':prezto:module:python:virtualenv' initialize 'no'
 ```
 
-On some systems, the `python` binary doesn't exist so in order to get
-virtualenvwrapper to work, the path needs to specified. We do our best to detect
-this, but sometimes it needs manual intervention.
-
-```sh
-zstyle ':prezto:module:python:virtualenvwrapper' python-path /opt/python3/bin/python3
-```
-
 Aliases
 -------
 

modules/python/init.zsh

@@ -115,15 +115,11 @@ if (( $+VIRTUALENVWRAPPER_VIRTUALENV || $+commands[virtualenv] )) && \
     # Fallback to 'virtualenvwrapper' without 'pyenv' wrapper if available
     # in '$path' or in an alternative location on a Debian based system.
     #
-    # If the python-path was manually specified, use that. Otherwise, if
-    # homebrew is installed and it wasn't overridden via environment variable
-    # we fall back to python3 then python2 in that order. This is needed to
-    # fix an issue with virtualenvwrapper as homebrew no longer shadows the
-    # system python.
-    zstyle -s ':prezto:module:python:virtualenvwrapper' python-path '_venv_python'
-    if [[ -n "$_venv_python" ]]; then
-      export VIRTUALENVWRAPPER_PYTHON=$_venv_python
-    elif [[ -z "$VIRTUALENVWRAPPER_PYTHON" ]] && (( $+commands[brew] )); then
+    # If homebrew is installed and the python location wasn't overridden via
+    # environment variable we fall back to python3 then python2 in that order.
+    # This is needed to fix an issue with virtualenvwrapper as homebrew no
+    # longer shadows the system python.
+    if [[ -z "$VIRTUALENVWRAPPER_PYTHON" ]] && (( $+commands[brew] )); then
       if (( $+commands[python3] )); then
         export VIRTUALENVWRAPPER_PYTHON=$commands[python3]
       elif (( $+commands[python2] )); then