A simple timer with audio alerts to run during an interview

interview-timer.py

#!/bin/env python3

import time
from datetime import datetime as dt

import numpy as np
import simpleaudio as sa
from scipy.signal import savgol_filter
from tqdm import tqdm


def beep_beep(freq_hz=330, seconds=0.16):
    SAMPLE_RATE = 44100  # 44100 samples per second
    nsamples = int(seconds * SAMPLE_RATE)

    t = np.linspace(0, seconds, num=nsamples, endpoint=False)

    silence1 = np.zeros(int(nsamples * 0.2))
    sine1 = np.sin(freq_hz * t * 2 * np.pi)
    silence2 = np.zeros(int(nsamples * 0.6))
    sine2 = sine1[:silence2.size]
    note = np.concatenate([silence1, sine1, silence2, sine2, silence1])
    note = savgol_filter(note, nsamples // 16, 3)  # smoothen

    # adjust volume
    audio = (330 / freq_hz) ** 1.6 * note * (2**14 - 1) / np.max(np.abs(note))

    audio = audio.astype(np.int16)
    play_obj = sa.play_buffer(audio, 1, 2, SAMPLE_RATE)
    play_obj.wait_done()


def wait_and_beep(duration, freq):
    for _ in tqdm(range(duration - 1), ncols=50):
        time.sleep(1)
    beep_beep(freq)


def main():
    start = dt.now()
    elapsed = lambda: str(dt.now() - start)[2:7]
    MINUTE = 60
    print(elapsed(), "introductions")
    wait_and_beep(4 * MINUTE, 220)
    print(elapsed(), "requirements")
    wait_and_beep(3 * MINUTE, 420)
    print(elapsed(), "capacity estimates")
    wait_and_beep(4 * MINUTE, 480)
    print(elapsed(), "high-level")
    wait_and_beep(8 * MINUTE, 330)
    print(elapsed(), "deep-dive")
    wait_and_beep(15 * MINUTE, 330)
    print(elapsed(), "conclude")


if __name__ == "__main__":
    main()