import sys, time
import pymedia.audio.sound as sound
import pymedia.audio.acodec as acodec

def work(name):
    f = open(name, 'wb')
    cparams= {'channels': 2, 'sample_rate': 48000, 'bitrate': 128000, 'id': acodec.getCodecID('mp3')}
    ac= acodec.Encoder( cparams )
    snd = sound.Input(48000, 2, sound.AFMT_S16_LE)
    snd.start()
        
    while True:
        s = snd.getData()
        if s and len(s):
            for fr in ac.encode(s):
                f.write(fr)
        else:
            time.sleep(0.003)
        
    snd.stop()

if __name__ == "__main__":
    work( sys.argv[1] )

python mymod.py

python (open python shell)
import mymod
mymod.work('t')