I think the best thing I've found for this personally is coccigrep, which works but I've only used it a couple of times. I'd like something I'd reach for about as often as I reach for grep. (Also I think these days you'd want it to be based on clang or something.)

One thing that does seem to be true is that the requirement to name types means that a textual grep is way more reliable than it is in C. If I want to find all places where a Python class is used in a large codebase, I might as well give up.