Minor PEP8 formatting changes

python/visualization.py

@@ -181,12 +181,12 @@ volume = dsp.ExpFilter(config.MIN_VOLUME_THRESHOLD,
 # Lots of buffer overflows could mean that FPS is set too high
 buffer_overflows = 1
 
+
 def microphone_update(stream):
     global y_roll, prev_rms, prev_exp
     # Retrieve and normalize the new audio samples
     try:
         y = np.fromstring(stream.read(samples_per_frame), dtype=np.int16)
-                                       #  exception_on_overflow=False), dtype=np.int16)
     except IOError:
         y = y_roll[config.N_ROLLING_HISTORY - 1, :]
         global buffer_overflows