This is because of how f-strings were initially implemented: I piggy-backed them off of "regular" strings, then post-parsed inside that string. But the restrict

This is because of how f-strings were initially implemented: I piggy-backed them off of "regular" strings, then post-parsed inside that string. But the restriction is that the entire f-string (after the f) needs to be a valid regular Python string. Since this: "this is a "regular" string" isn't valid, then neither is this: f"dict lookup: {d["key"]}" However, we've talked about changing f-string parsing from a "post-process regular strings" mode, to instead having the tokenizer and parser themselves aware of f-strings. When we do that, the f-string example above will work. (edit for formatting)