Examples: Don't use the logging module, proper exit codes

Author: mgeier

examples/play_file.py

@@ -10,7 +10,6 @@
 
 """
 import argparse
-import logging
 
 
 def int_or_str(text):
@@ -33,7 +32,7 @@ def int_or_str(text):
     sd.play(data, fs, device=args.device, blocking=True)
     status = sd.get_status()
     if status:
-        logging.warning(str(status))
+        parser.exit('Error during playback: ' + str(status))
 except KeyboardInterrupt:
     parser.exit('\nInterrupted by user')
 except Exception as e:

examples/play_long_file.py

@@ -10,12 +10,13 @@
 larger than the available RAM.
 
 """
-from __future__ import division
+from __future__ import division, print_function
 import argparse
 try:
     import queue  # Python 3.x
 except ImportError:
     import Queue as queue  # Python 2.x
+import sys
 import threading
 
 def int_or_str(text):
@@ -47,12 +48,13 @@ def int_or_str(text):
 def callback(outdata, frames, time, status):
     assert frames == args.blocksize
     if status.output_underflow:
-        parser.error('An output underflow occurred: increase blocksize?')
+        print('Output underflow: increase blocksize?', file=sys.stderr)
         raise sd.CallbackAbort
+    assert not status
     try:
         data = q.get_nowait()
     except queue.Empty:
-        parser.error('Buffer is empty: increase buffersize?')
+        print('Buffer is empty: increase buffersize?', file=sys.stderr)
         raise sd.CallbackAbort
     if len(data) < len(outdata):
         outdata[:len(data)] = data

examples/plot_input.py

@@ -1,7 +1,12 @@
 #!/usr/bin/env python3
-"""Plot the live microphone signal(s) with matplotlib."""
+"""Plot the live microphone signal(s) with matplotlib.
+
+Matplotlib and NumPy have to be installed.
+
+"""
 import argparse
-from queue import Queue, Empty
+import queue
+import sys
 
 
 def int_or_str(text):
@@ -39,15 +44,15 @@ def int_or_str(text):
 if any(c < 1 for c in args.channels):
     parser.error('argument CHANNEL: must be >= 1')
 mapping = [c - 1 for c in args.channels]  # Channel numbers start with 1
-queue = Queue()
+q = queue.Queue()
 
 
 def audio_callback(indata, frames, time, status):
     """This is called (from a separate thread) for each audio block."""
     if status:
-        print(status, flush=True)
+        print(status, file=sys.stderr)
     # Fancy indexing with mapping creates a (necessary!) copy:
-    queue.put(indata[::args.downsample, mapping])
+    q.put(indata[::args.downsample, mapping])
 
 
 def update_plot(frame):
@@ -61,8 +66,8 @@ def update_plot(frame):
     block = True  # The first read from the queue is blocking ...
     while True:
         try:
-            data = queue.get(block=block)
-        except Empty:
+            data = q.get(block=block)
+        except queue.Empty:
             break
         shift = len(data)
         plotdata = np.roll(plotdata, -shift, axis=0)
@@ -81,7 +86,7 @@ def update_plot(frame):
 
     if args.list_devices:
         print(sd.query_devices())
-        parser.exit()
+        parser.exit(0)
     if args.samplerate is None:
         device_info = sd.query_devices(args.device, 'input')
         args.samplerate = device_info['default_samplerate']

examples/rec_unlimited.py

@@ -3,12 +3,11 @@
 
 PySoundFile (https://github.com/bastibe/PySoundFile/) has to be installed!
 
-WARNING: This works only in Python 3.x!
-
 """
 import argparse
 import tempfile
-from queue import Queue
+import queue
+import sys
 
 
 def int_or_str(text):
@@ -42,21 +41,21 @@ def int_or_str(text):
 
     if args.list_devices:
         print(sd.query_devices())
-        parser.exit()
+        parser.exit(0)
     if args.samplerate is None:
         device_info = sd.query_devices(args.device, 'input')
         # soundfile expects an int, sounddevice provides a float:
         args.samplerate = int(device_info['default_samplerate'])
     if args.filename is None:
         args.filename = tempfile.mktemp(prefix='rec_unlimited_',
                                         suffix='.wav', dir='')
-    queue = Queue()
+    q = queue.Queue()
 
     def callback(indata, frames, time, status):
         """This is called (from a separate thread) for each audio block."""
         if status:
-            print(status, flush=True)
-        queue.put(indata.copy())
+            print(status, file=sys.stderr)
+        q.put(indata.copy())
 
     # Make sure the file is opened before recording anything:
     with sf.SoundFile(args.filename, mode='x', samplerate=args.samplerate,
@@ -67,9 +66,10 @@ def callback(indata, frames, time, status):
             print('press Ctrl+C to stop the recording')
             print('#' * 80)
             while True:
-                file.write(queue.get())
+                file.write(q.get())
 
 except KeyboardInterrupt:
-    parser.exit('\nRecording finished: ' + repr(args.filename))
+    print('\nRecording finished: ' + repr(args.filename))
+    parser.exit(0)
 except Exception as e:
     parser.exit(type(e).__name__ + ': ' + str(e))

examples/spectrogram.py

@@ -1,7 +1,6 @@
 #!/usr/bin/env python3
 """Show a text-mode spectrogram using live microphone data."""
 import argparse
-import logging
 import math
 import numpy as np
 import shutil
@@ -59,19 +58,19 @@ def int_or_str(text):
 
     if args.list_devices:
         print(sd.query_devices())
-        parser.exit()
+        parser.exit(0)
 
     samplerate = sd.query_devices(args.device, 'input')['default_samplerate']
 
     delta_f = (high - low) / (args.columns - 1)
     fftsize = math.ceil(samplerate / delta_f)
     low_bin = math.floor(low / delta_f)
 
-    cumulated_status = sd.CallbackFlags()
-
     def callback(indata, frames, time, status):
-        global cumulated_status
-        cumulated_status |= status
+        if status:
+            text = ' ' + str(status) + ' '
+            print('\x1b[34;40m', text.center(args.columns, '#'),
+                  '\x1b[0m', sep='', flush=True)
         if any(indata):
             magnitude = np.abs(np.fft.rfft(indata[:, 0], n=fftsize))
             magnitude *= args.gain / fftsize
@@ -97,8 +96,6 @@ def callback(indata, frames, time, status):
                     print('\x1b[31;40m', usage_line.center(args.columns, '#'),
                           '\x1b[0m', sep='', flush=True)
                     break
-    if cumulated_status:
-        logging.warning(str(cumulated_status))
 except KeyboardInterrupt:
     parser.exit('Interrupted by user')
 except Exception as e:

examples/wire.py

@@ -31,11 +31,9 @@ def int_or_str(text):
 try:
     import sounddevice as sd
 
-    cumulated_status = sd.CallbackFlags()
-
     def callback(indata, outdata, frames, time, status):
-        global cumulated_status
-        cumulated_status |= status
+        if status:
+            print(status, flush=True)
         outdata[:] = indata
 
     with sd.Stream(device=(args.input_device, args.output_device),
@@ -46,9 +44,6 @@ def callback(indata, outdata, frames, time, status):
         print('press Return to quit')
         print('#' * 80)
         input()
-
-    if cumulated_status:
-        logging.warning(str(cumulated_status))
 except KeyboardInterrupt:
     parser.exit('\nInterrupted by user')
 except Exception as e: