PyAudio.open, how to use?

I'm trying to make a pyaudio input stream开发者_如何转开发 but can't figure out how to make it. What I did is:

a = pyaudio.PyAudio()

Then tried to call a.open() but I don't know the arguments I should type in. It asks me to check Stream.init for a reference, but I don't know what a PA_MANAGER is and the documentation isn't useful at all about it.

Perhaps you could start by modfying some of the examples?