If its just playback and does not need to be synchronised to anything then you can just do the following:

# Open stream with correct settings
stream = self.p.open(format=pyaudio.paFloat32,
                         channels=CHANNELS,
                         rate=48000,
                         output=True,
                         output_device_index=1
                         )
# Assuming you have a numpy array called samples
data = samples.astype(np.float32).tostring()
stream.write(data)

I use this method and it works fine for me. If you need to record at the same time then this won't work.

If you are just looking to generate audio tones then below code may be useful,

It does need pyaudio that can be installed as

pip install pyaudio

Sample Code

#Play a fixed frequency sound.
from __future__ import division
import math
import pyaudio

#See http://en.wikipedia.org/wiki/Bit_rate#Audio
BITRATE = 44100 #number of frames per second/frameset.      

#See http://www.phy.mtu.edu/~suits/notefreqs.html
FREQUENCY = 2109.89 #Hz, waves per second, 261.63=C4-note.
LENGTH = 1.2 #seconds to play sound

NUMBEROFFRAMES = int(BITRATE * LENGTH)
RESTFRAMES = NUMBEROFFRAMES % BITRATE
WAVEDATA = ''    

for x in xrange(NUMBEROFFRAMES):
WAVEDATA = WAVEDATA+chr(int(math.sin(x/((BITRATE/FREQUENCY)/math.pi))*127+128))    

#fill remainder of frameset with silence
for x in xrange(RESTFRAMES): 
WAVEDATA = WAVEDATA+chr(128)

p = pyaudio.PyAudio()
stream = p.open(format = p.get_format_from_width(1), 
            channels = 1, 
            rate = BITRATE, 
            output = True)
stream.write(WAVEDATA)
stream.stop_stream()
stream.close()
p.terminate()

Code is slightly modified from this askubuntu site

You can directly stream the data through pyaudio, there is no need to write and read a .wav file.

import pyaudio
p = pyaudio.PyAudio()
stream = p.open(format=pyaudio.paFloat32,
                channels=1,
                rate=44100,
                frames_per_buffer=1024,
                output=True,
                output_device_index=1
                )
samples = np.sin(np.arange(50000)/20)
stream.write(samples.astype(np.float32).tostring())
stream.close()