Add type hints

adafruit_dht.py

@@ -39,6 +39,12 @@
 except (ImportError, NotImplementedError):
     pass  # This is OK, we'll try to bitbang it!
 
+try:
+    # Used only for typing
+    from typing import Union
+    from microcontroller import Pin
+except ImportError:
+    pass
 
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_DHT.git"
@@ -49,7 +55,7 @@ class DHTBase:
 
     __hiLevel = 51
 
-    def __init__(self, dht11, pin, trig_wait, use_pulseio):
+    def __init__(self, dht11: bool, pin: Pin, trig_wait: int, use_pulseio: bool):
         """
         :param boolean dht11: True if device is DHT11, otherwise DHT22.
         :param ~board.Pin pin: digital pin used for communication
@@ -68,16 +74,16 @@ def __init__(self, dht11, pin, trig_wait, use_pulseio):
         # We don't use a context because linux-based systems are sluggish
         # and we're better off having a running process
         if self._use_pulseio:
-            self.pulse_in = PulseIn(self._pin, 81, True)
+            self.pulse_in = PulseIn(self._pin, maxlen=81, idle_state=True)
             self.pulse_in.pause()
 
-    def exit(self):
-        """ Cleans up the PulseIn process. Must be called explicitly """
+    def exit(self) -> None:
+        """Cleans up the PulseIn process. Must be called explicitly"""
         if self._use_pulseio:
             print("De-initializing self.pulse_in")
             self.pulse_in.deinit()
 
-    def _pulses_to_binary(self, pulses, start, stop):
+    def _pulses_to_binary(self, pulses: array.array, start: int, stop: int) -> int:
         """Takes pulses, a list of transition times, and converts
         them to a 1's or 0's.  The pulses array contains the transition times.
         pulses starts with a low transition time followed by a high transistion time.
@@ -106,7 +112,7 @@ def _pulses_to_binary(self, pulses, start, stop):
 
         return binary
 
-    def _get_pulses_pulseio(self):
+    def _get_pulses_pulseio(self) -> array.array:
         """_get_pulses implements the communication protocol for
         DHT11 and DHT22 type devices.  It sends a start signal
         of a specific length and listens and measures the
@@ -134,7 +140,7 @@ def _get_pulses_pulseio(self):
                 pulses.append(self.pulse_in.popleft())
         return pulses
 
-    def _get_pulses_bitbang(self):
+    def _get_pulses_bitbang(self) -> array.array:
         """_get_pulses implements the communication protcol for
         DHT11 and DHT22 type devices.  It sends a start signal
         of a specific length and listens and measures the
@@ -179,7 +185,7 @@ def _get_pulses_bitbang(self):
                 pulses.append(min(pulses_micro_sec, 65535))
         return pulses
 
-    def measure(self):
+    def measure(self) -> None:
         """measure runs the communications to the DHT11/22 type device.
         if successful, the class properties temperature and humidity will
         return the reading returned from the device.
@@ -250,7 +256,7 @@ def measure(self):
             self._humidity = new_humidity
 
     @property
-    def temperature(self):
+    def temperature(self) -> Union[int, float, None]:
         """temperature current reading.  It makes sure a reading is available
 
         Raises RuntimeError exception for checksum failure and for insufficient
@@ -260,7 +266,7 @@ def temperature(self):
         return self._temperature
 
     @property
-    def humidity(self):
+    def humidity(self) -> Union[int, float, None]:
         """humidity current reading. It makes sure a reading is available
 
         Raises RuntimeError exception for checksum failure and for insufficient
@@ -276,7 +282,7 @@ class DHT11(DHTBase):
     :param ~board.Pin pin: digital pin used for communication
     """
 
-    def __init__(self, pin, use_pulseio=_USE_PULSEIO):
+    def __init__(self, pin: Pin, use_pulseio: bool = _USE_PULSEIO):
         super().__init__(True, pin, 18000, use_pulseio)
 
 
@@ -286,5 +292,5 @@ class DHT22(DHTBase):
     :param ~board.Pin pin: digital pin used for communication
     """
 
-    def __init__(self, pin, use_pulseio=_USE_PULSEIO):
+    def __init__(self, pin: Pin, use_pulseio: bool = _USE_PULSEIO):
         super().__init__(False, pin, 1000, use_pulseio)