I have actually highlighted a small neat recipe for doing such unpacking, that I use for parsing arbitrary parameters in Evoque Templating. I never needed to handle "callable" parameters though, as you do in your 3rd string example, so the little "unpack_symbol" recipe I have publiched earlier does not handle it... anyhow, what I referring to are:
Evoque Templating: http://evoque.gizmojo.org/ Code highlight: http://gizmojo.org/code/unpack_symbol/ However, a little variation of the aboverecipe can do what you are looking for, in a rather cute way. The difference is to make the original recipe handle "callable strings", and I achieve this by modifying the recipe like so: class callable_str(str): def __call__(s, *args): return s+str(args) class _UnpackGlobals(dict): def __getitem__(self, name): return callable_str(name) def unpack_symbol(symbol, globals=_UnpackGlobals()): """ If compound symbol (list, tuple, nested) unpack to atomic symbols """ return eval(symbol, globals, None) Now, calling unpack_symbol() on each sample string gives the following tuple of strings: >>> unpack_symbol('foo, bar, baz') ('foo', 'bar', 'baz') >>> unpack_symbol('foo, "bar, baz", blurf') ('foo', 'bar, baz', 'blurf') >>> unpack_symbol('foo, bar(baz, blurf), mumble') ('foo', "bar('baz', 'blurf')", 'mumble') >>> Mario Ruggier -- http://mail.python.org/mailman/listinfo/python-list
