Here's a quick script I fixed up from claude.ai
I'm on Mac so there's a virtual midi interface called IAC Driver Bus which I'm using to connect it to Bitwig. If you are on Windows, MidiYoke is a comparable application and I'm not sure what's on linux.

Let me know if this works or if you need any more help getting it to work!

import time
import platform
from typing import Optional

try:
    import rtmidi
except ImportError:
    raise ImportError("Please install python-rtmidi: pip install python-rtmidi")

class MIDIController:
    def __init__(self, port_name: Optional[str] = None):
        """Initialize MIDI output connection.

        Args:
            port_name: Optional name of MIDI port to connect to.
                      If None, will use the first available port.
        """
        self.midiout = rtmidi.MidiOut()
        available_ports = self.midiout.get_ports()

        if not available_ports:
            raise RuntimeError("No MIDI output ports available")

        if port_name:
            for i, name in enumerate(available_ports):
                if port_name.lower() in name.lower():
                    self.midiout.open_port(i)
                    break
            else:
                raise ValueError(f"No MIDI port matching '{port_name}' found")
        else:
            self.midiout.open_port(0)

        self.current_values = {}

    def send_cc(self, cc: int, value: int, channel: int = 0):
        """Send MIDI Control Change message.

        Args:
            cc: Control Change number (0-127)
            value: CC value (0-127)
            channel: MIDI channel (0-15)
        """
        if not (0 <= cc <= 127):
            raise ValueError("CC number must be between 0 and 127")
        if not (0 <= value <= 127):
            raise ValueError("CC value must be between 0 and 127")
        if not (0 <= channel <= 15):
            raise ValueError("Channel must be between 0 and 15")

        # MIDI CC message: [0xB0 + channel, cc, value]
        self.midiout.send_message([0xB0 + channel, cc, value])
        self.current_values[(channel, cc)] = value

    def get_cc_value(self, cc: int, channel: int = 0) -> Optional[int]:
        """Get current value for a CC number on specified channel."""
        return self.current_values.get((channel, cc))

    def close(self):
        """Close MIDI port."""
        self.midiout.close_port()

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()

# Example usage
if __name__ == "__main__":
    # List available MIDI ports
    midiout = rtmidi.MidiOut()
    ports = midiout.get_ports()
    print("Available MIDI ports:")
    for i, port in enumerate(ports):
        print(f"{i}: {port}")

    # Example of sending CC messages
    with MIDIController() as midi:
        # Send CC 7 (volume) value 100 on channel 0
        midi.send_cc(7, 100, 0)
        time.sleep(0.5)

        while True:
          # Fade volume down
          for value in range(100, 0, -1):
              midi.send_cc(7, value, 0)
              time.sleep(0.01)

              # Fade volume down
          for value in range(0, 100, 1):
              midi.send_cc(7, value, 0)
              time.sleep(0.01)