I one had a database-backed website serving 50k unique visitors/day written in Django and hosted on a low-budget vps. Worked like a charm with very few hiccups.
Right? I do not understand why the comparison of Python is always, "But when you hit 10 million daily users, you are really going to be feeling the scaling pain." You can hit a very serious audience size before ever having to worry about performance characteristics at all. Computers are fast.