[Python-ideas] Adding bytes.frombuffer() constructor

bytearray is used as read / write buffer in asyncio. When implementing reading stream, read() API may be defined as returns "bytes". To get front n bytes from bytearray, there are two ways. 1. bytes(bytearray[:n]) 2. bytes(memoryview(bytearray)[:n]) (1) is simplest, but it produces temporary bytearray having n bytes. While (2) is more efficient than (1), it uses still temporary memoryview object, and it looks bit tricky. I want simple, readable, and temporary-less way to get part of bytearray as bytes. The API I propose looks like this: bytes.frombuffer(byteslike, length=-1, offset=0) How do you feel about it? -- INADA Naoki