Python Sine wave outputting random sounds

Question

I am trying to build a python synthesizer using pygame.

I followed some tutorials and combined some code from different sources, but when playing the output as a sound, I get random noise for different frequencies.

Here is the code with irrelevant parts ommitted:

import key_manager as km
from array import array 
import pygame
from pygame import mixer
from pygame.mixer import Sound, get_init,  pre_init
import time
import numpy as np
import math

class Note(pygame.mixer.Sound): 

    def __init__(self, frequency, volume=.1): 
        self.frequency = frequency 
        if synth_type == "sine":
            Sound.__init__(self, self.build_samples_sine()) 
        self.set_volume(volume) 

    def build_samples_sine(self): 
        period = int(round(get_init()[0] / self.frequency)) 
        samples = array("h", [0] * period * 2) 
        amplitude = 2 ** (abs(get_init()[1]) - 1) - 1 
        for time in range(period * 2): 
            samples[time] = int(round(amplitude * math.sin(2 * math.pi * self.frequency * time)))
        return samples

pre_init(44100, -16, 1, 1024)
pygame.init()
frequency = <whatever frequency I am trying to play>
mixer.Channel(frequency).play(note, -1)

Thanks for any help or advice.