Only tools, one-offs, and small internal products at Google can use Python. In general, for production it is disallowed (with exception of YouTube). They learned with YouTube that Python doesn't scale well to hundreds or thousands of developers. Even Mondrian, the code review system started by Guido and written in python, was replaced by something more scalable.
Yeah, I'd say Java and C++ are about equally prevalent at Google. A lot of the older products and core infra is still C++, and a ton of new stuff is Java (See: Android).
