You don't actually need a tool for this. The Python standard library comes with the wave module for writing .wav files, and of course raw .pcm files can be just opened as plain binary files, and if you need to do any simple transformations that aren't trivial with a list comprehension, they're trivial with audioop.
For example, this is a complete program from converting stereo 16-bit little-endian 44.1k PCM files to WAV files:
import sys
import wave
for arg in sys.argv[1:]:
with open(arg, 'rb') as pcmfile:
pcmdata = pcmfile.read()
with wave.open(arg+'.wav', 'wb') as wavfile:
wavfile.setparams((2, 2, 44100, 0, 'NONE', 'NONE'))
wavfile.writeframes(pcmdata)
In older versions of Python, you may have to use with contextlib.closing(wave.open(…)) (or an explicit open and close instead of a with statement).
