Updating progress bar in Tkinter simultaneously while recording audio Python3 - multithreading

Question

My goal for this simple program is to be able to show a progress bar of time the mic has been recording(range from 0 - 30 seconds). I am using the Tkinter library, Python 3.6, and PyAudio to record.
I finished writing the code for the individual parts(recording + updating progress bar) but I don't know how to change the code so that they happen at the same time(not one after the other). Also, I've realized that while I am recording, the GUI freezes(I can't click or resize buttons), I am also wondering about how to fix this issue. After doing some more research, I have a feeling that the answer lies with multi-threading or root.update() but I am not sure.
I am looking for a code example of recording audio while I simultaneously update the progress bar.
Here is an example:
from tkinter import *
from tkinter import ttk
import tkinter as tk
import pyaudio
import numpy as np
np.random.seed(123) # for reproducibility
import matplotlib
matplotlib.use('Agg') # No pictures displayed
class Test_GUI(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
root = self
label_title = Label(root, text="Progress Bar Recording Sample")
label_title.pack(fil="x")
topFrame = Frame(root)
topFrame.pack(side=TOP)
self.recordButton = Button(topFrame, text="Record", command=self.start)
self.recordButton.pack(side=LEFT)
self.progress = ttk.Progressbar(topFrame, orient="horizontal",
length=200, mode="determinate")
self.min = 0
self.maxMin = 0
self.progress.pack(side=RIGHT)
# recording attributes.
self.CHUNK = 1024
self.FORMAT = pyaudio.paInt16
self.CHANNELS = 2
self.RATE = 44100
self.RECORD_SECONDS = 15
self.WAVE_OUTPUT_FILENAME = "/Users/Sree/Desktop/PythonPrograms/audio_output_test.wav"
def start(self):
print("here")
self.progress["value"] = 0
self.maxMin = 30
self.progress["maximum"] = 30
'''
I need the following 2 lines to happen at the same time
the progress bar needs to update from 1-30 seconds(which is the time I am recording)
'''
self.record()
self.update_progress() #The progress bar is from 0 sec to 30 sec indicating what percentage of the time the mic has been recording for.
def update_progress(self):
self.min += 0.1
self.progress["value"] = self.min
if self.min < self.maxMin:
# update after 100 ms
self.after(100, self.update_progress)
def record(self):
p = pyaudio.PyAudio()
stream = p.open(format=self.FORMAT,
channels=self.CHANNELS,
rate=self.RATE,
input=True,
frames_per_buffer=self.CHUNK)
print("* recording")
frames = []
for i in range(0, int(self.RATE / self.CHUNK * self.RECORD_SECONDS)):
data = stream.read(self.CHUNK)
frames.append(data)
print("* done recording")
stream.stop_stream()
stream.close()
p.terminate()
wf = wave.open(self.WAVE_OUTPUT_FILENAME, 'wb')
wf.setnchannels(self.CHANNELS)
wf.setsampwidth(p.get_sample_size(self.FORMAT))
wf.setframerate(self.RATE)
wf.writeframes(b''.join(frames))
wf.close()
app = Test_GUI()
app.mainloop()

Answer 1

To prevent the GUI from freezing while recording, you need to launch the recording in a separate thread. To do so, you can use the threading module for instance and replace self.record() in your start method by:
record_thread = threading.Thread(target=self.record, daemon=True)
record_thread.start()