For python string template is there a clean way to extract the variable names in the template string.

I actually want to to be able to write template stings into a textfield on and then substitue the variables for other more complex looking variables.

So for example I would get user inputted template into a variable

```
t = Template(( request.POST['comment'] ))

```

the comment string maybe 

```
'$who likes $what'

```

I need an array of the variables names so I can convert the string to something like

```
{{{who}}} likes {{{what}}}

```

Maybe there is also a better way to approach this.