WAV writing sample, a single note in one second (44100 Hz)

import wave
import math
f = wave.open("test.wav", "wb")
f.setnchannels(1)
f.setframerate(44100)
f.setsampwidth(1)
#for frec in [261.63, 277.18, 293.66, 311.13, 329.63, 349.23, 369.99, 392.00, 415.30, 440.00, 466.16, 493.88, 523.25]:
ampl = 96.0
for frec in [440.00]:
        data = bytearray()
        for i in range(44100):
                data += chr(int(math.sin((i / 44100.0) * math.pi * frec * 2.0) * ampl + 128.0))
        f.writeframesraw(data)
f.close()