python-info: provide python version info for theming

Closes #1173
Closes #958

modules/python/README.md

@@ -135,6 +135,10 @@ following style in the `prompt_name_setup` function.
 Then add `$python_info[virtualenv]` to `$PROMPT` or `$RPROMPT` and call
 `python-info` in the `prompt_name_preexec` hook function.
 
+Similarly, you can use `:prezto:module:python:info:version:format` with `%v` for
+the version and add `$python_info[version]` to your prompt for the current
+python version/
+
 Authors
 -------
 

modules/python/functions/python-info

@@ -11,6 +11,8 @@
 
 local virtualenv_format
 local virtualenv_formatted
+local version_format
+local version_formatted
 
 # Clean up previous $python_info.
 unset python_info
@@ -30,4 +32,10 @@ if [[ -n "$CONDA_DEFAULT_ENV" ]]; then
   python_info[virtualenv]="$virtualenv_formatted"
 fi
 
+zstyle -s ':prezto:module:python:info:version' format 'version_format'
+if [[ -n "$version_format" ]]; then
+  zformat -f version_formatted "$version_format" "v:${$(python3 --version)#Python }"
+  python_info[version]="$version_formatted"
+fi
+
 # }