Reading from asyncio StreamReader

Question

I am trying to extend the python asyncio HTTP server example that uses a streaming reader/writer (code). If I understand it correctly, the example handler read 100 bytes from the reader and echoes it back to the client through the writer. I am trying to read more than 100 bytes... reading until there is nothing more to read would be nice.

I have tried letting the read() function read as much as possible,

data = yield from reader.read()

but that seems to block forever. So I tried reading chunks until the EOF is reached,

while not reader.at_eof():
    data += yield from reader.read(100)

and while this retrieves more of the data, it to seems to block on the read call instead of exiting the while loop.

How can I get the entire message from the client using the stream reader?

Answer 1

You should check if StreamReader.read returned an empty bytes object to signal an EOF:

data = bytearray()
while True:
    chunk = yield from reader.read(100)
    if not chunk:
        break
    data += chunk

Also, consider using aiohttp if you need a fully functional HTTP client.