added main darkmut function and minor tweaks

darkmute.py

-#!/usr/local/bin/python
-
 import RPi.GPIO as GPIO
 import time
+import snapcast.control
 
-GPIO.setmode(GPIO.BOARD)
+SENSOR_PIN = 7
 
-pin_to_circuit = 7
 
-def rc_time (pin_to_circuit):
-    count = 0
+def measure_brightness(pin_to_circuit):
+    '''Measure brightness using photoresistor-capacitor circuit.'''
+    charge_time = 0
 
     GPIO.setup(pin_to_circuit, GPIO.OUT)
     GPIO.output(pin_to_circuit, GPIO.LOW)
@@ -17,15 +16,21 @@ def rc_time (pin_to_circuit):
     GPIO.setup(pin_to_circuit, GPIO.IN)
 
     while (GPIO.input(pin_to_circuit) == GPIO.LOW):
-        count += 1
+        charge_time += 1
+
+    return 1/charge_time
+
 
-    return count
+def dark_mute():
+    GPIO.setmode(GPIO.BOARD)
+    try:
+        while True:
+            print(measure_brightness(SENSOR_PIN))
+    except KeyboardInterrupt:
+        pass
+    finally:
+            GPIO.cleanup()
 
-try:
-    while True:
-        print rc_time(pin_to_circuit)
-except KeyboardInterrupt:
-    pass
-finally:
-        GPIO.cleanup()
 
+if __name__ == '__main__':
+    dark_mute()