AttributeError in python-rtmidi sample code

Question

I installed rtmidi for python and was able to import it. But when I tried to run the whole usage example given here: https://pypi.python.org/pypi/python-rtmidi, I got this error:

AttributeError: 'rtmidi_python.MidiOut' object has no attribute 'get_ports'

Here's the full code:

import time
import rtmidi_python as rtmidi

midiout = rtmidi.MidiOut()
available_ports = midiout.get_ports()

if available_ports:
    midiout.open_port(0)
else:
    midiout.open_virtual_port("My virtual output")

note_on = [0x90, 60, 112] # channel 1, middle C, velocity 112
note_off = [0x80, 60, 0]
midiout.send_message(note_on)
time.sleep(0.5)
midiout.send_message(note_off)

del midiout

I modified the code a little bit in the import part, because somehow it doesn't work when I put import rtmidi but works when I put import rtmidi_python.

I'm using Python 3.5. Any help will be appreciated, thanks!

Answer 1

The reason you're having trouble is that you are running sample code for python-rtmidi, but you installed rtmidi-python. I kid you not, these are two separate libraries that do the same thing with almost the same interface. It's nuts! You have two options:

1. you can install the correct library by doing: pip install python-rtmidi

2. you can modify your code so that it works with rtmidi-python as follows:

   import time
   import rtmidi_python as rtmidi
   
   midiout = rtmidi.MidiOut()
   available_ports = midiout.ports
   
   if available_ports:
       midiout.open_port(0)
   else:
       midiout.open_virtual_port("My virtual output")
   
   note_on = [0x90, 60, 112] # channel 1, middle C, velocity 112
   note_off = [0x80, 60, 0]
   midiout.send_message(note_on)
   time.sleep(0.5)
   midiout.send_message(note_off)
   
   del midiout
   

You see: instead of doing get_ports(), you simply references the ports attribute.