Starting two methods at the same time in Python

parallel-processing, python

Solution

import threading,time
def play1():
    while time.time() <= start_time:
        pass
    threading.Thread(target=listen_to_audio).start()
def play2():
    while time.time() <= start_time:
        pass
    threading.Thread(target=play_audio).start()
start_time=time.time()+20
threading.Thread(target=play1).start()
threading.Thread(target=play2).start()

This should work for you, it starts each function, and in each function it waits until it is the right time :)

Problem

I am trying to run two methods at the same time in Python. One of them plays a sound and the other one records it. Both methods work fine but I could not figure it out how to start them at the same time both multiprocessing and threading were tried. Whereas I am almost sure now that it can't be solved with threading. ``` def listen_to_audio() def play_audio() ``` Any ideas? (They don't have to finish at the same time but they should both start within a second.) That is the code, sorry for not posting it in the beginning: ``` import pyaudio import wave import sys import time from math import * from getopt import * import threading def make_sin(f0=1000.,ampl=30000,rate=22050,length=5.): a = 2. * pi * f0/rate n = int(rate * length) wav='' for i in range(0, n): f = int(ampl*sin(a*i)) wav += chr(f & 0xFF) + chr((f & 0xFF00) >> 8) return wav def play_audio(forHowLong): data = make_sin(f0=1000.,ampl=30000,rate=22050,length=5.) p = pyaudio.PyAudio() #sets up portaudio system stream = p.open(format=p.get_format_from_width(2), channels=1, rate=22050, output=True) start = time.time() while time.time() < start + forHowLong*0.5: stream.write(data) stream.stop_stream() stream.close() p.terminate() def listen_to_audio(forHowLong): CHUNK = 1024 FORMAT = pyaudio.paInt16 CHANNELS = 2 RATE = 44100 RECORD_SECONDS = forHowLong WAVE_OUTPUT_FILENAME = "output.wav" p = pyaudio.PyAudio() stream = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, input=True, frames_per_buffer=CHUNK) print("* recording") frames = [] for i in range(0, int(RATE / CHUNK * RECORD_SECONDS)): data = stream.read(CHUNK) frames.append(data) print("* done recording") stream.stop_stream() stream.close() p.terminate() wf = wave.open(WAVE_OUTPUT_FILENAME, 'wb') wf.setnchannels(CHANNELS) wf.setsampwidth(p.get_sample_size(FORMAT)) wf.setframerate(RATE) wf.writeframes(b''.join(frames)) wf.close() def main(): #start play_audio and record_audio here at the same time if __name__ == "__main__": main() ```

Original source