How to create a white noise signal in Python, and filter the noise signal with bandpass filter?

Question

I'm doing a project about speech processing. I wonder how to create a white noise signal in Python, and filter the noise signal with bandpass filter?

import pyaudio
import numpy as np
import scipy.signal as signal

CHUNK = 64 #the block size
Q = 50

pa = pyaudio.PyAudio()
stream = pa.open(format=pyaudio.paFloat32,
                            channels=1,
                            rate=44100,
                            output=True)
while True:
    noise = np.random.uniform(-1,1,CHUNK)
    b,a = signal.iirfilter(1,[2*500*(1-1/(2*Q))/44100,2*500*(1+1/(2*Q))/44100])
    output = signal.lfilter(b,a,noise)
    output.astype(np.float32)
    output = output.tobytes()
    stream.write(output)

Is the code right? And what is the difference between signal.iirfilter and signal.butter? Thank you very much.