Refactor shared code and make requested changes

Python_Examples/PiLiteLib.py

@@ -0,0 +1,63 @@
+from collections import deque
+from time import sleep
+
+import requests
+import serial
+
+
+class PiLiteBoard(object):
+    def __init__(self):
+        self.ser = serial.Serial("/dev/ttyAMA0", baudrate=9600, timeout=3.0)
+        self.ser.write("$$$SPEED50\r")
+
+    def write(self, text):
+        text = text.encode('utf-8')
+        while text:
+            self.ser.write(text[:14])
+            text = text[14:]
+            sleep(3)
+
+
+def poll_for_updates(source, sink, interval=60, repeat=True):
+    oldstatus = None
+    while True:
+        try:
+            status = source.message()
+            if repeat or status != oldstatus:
+                print(status)
+                oldstatus = status
+                sink.write(status)
+        except (KeyboardInterrupt, SystemExit):
+            raise
+        except Exception as e:
+            print("Error:" + str(e))
+            sink.write("...oops...error...")
+            sink.write(str(e))
+        sleep(interval)
+
+
+class JSONPoll(object):
+    def __init__(self, url, message_format, params=None):
+        self.url = url
+        self.message_format = message_format
+        self.params = params or {}
+
+    def message(self):
+        data = requests.get(self.url, params=self.params).json()
+        return self.message_format.format(**self.mung_data(data))
+
+    def mung_data(self, data):
+        return data
+
+
+class CyclingSources(object):
+    def __init__(self, *sources):
+        self.sources = deque(sources)
+
+    def message(self):
+        message = self.sources[0].message()
+        self.sources.rotate(-1)
+        return message
+
+    def __len__(self):
+        return len(self.sources)

Python_Examples/PiLiteStock.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+import urllib
+
+from PiLiteLib import PiLiteBoard, poll_for_updates, JSONPoll
+
+
+class StockPoll(JSONPoll):
+    def __init__(self, stock, message_format=""):
+        """ Encoding a space in the url a + breaks YQL, so requests params
+            handling can't be used
+        """
+        default_format = "{symbol} {Bid},{PercentChange}"
+	base_url = "http://query.yahooapis.com/v1/public/yql"
+        querystring = "from yahoo.finance.quotes where symbol='%s'"
+        fmt = "format=json"
+        env = "env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys"
+        url = "%s?q=select%%20*%%20%s&%s&%s"%(base_url, urllib.quote(querystring%stock), fmt, env)
+	super(StockPoll, self).__init__(url, message_format or default_format)
+
+    def mung_data(self, data):
+        """ Drill down to the result to make message_format more readable"""
+        return super(StockPoll, self).mung_data(data['query']['results']['quote'])
+
+
+
+def main():
+    source = StockPoll("MSFT")
+    sink = PiLiteBoard()
+    print("ready")
+    sink.write("ready  ")
+    poll_for_updates(source, sink)
+
+
+if __name__ == "__main__":
+    main()

Python_Examples/PiLiteTwitter.py

@@ -33,23 +33,11 @@
 
 import ConfigParser
 import os
-from time import sleep
 
 import twitter
-import serial
 
 
-class PiLiteBoard(object):
-    def __init__(self):
-        self.ser = serial.Serial("/dev/ttyAMA0", baudrate=9600, timeout=3.0)
-        self.ser.write("$$$SPEED50\r")
-
-    def write(self, text):
-        text = text.encode('utf-8')
-        while text:
-            self.ser.write(text[:14])
-            text = text[14:]
-            sleep(3)
+from PiLiteLib import PiLiteBoard, poll_for_updates
 
 
 class TwitterTimeline(object):
@@ -67,30 +55,12 @@ def message(self):
 	return "@%s::%s..."%(status.GetUser().GetScreenName(), status.GetText())
 
 
-def poll_for_updates(source, sink, interval=60):
-    oldstatus = None
-    while True:
-        try:
-            status = source.message()
-            if status != oldstatus:
-                print(status)
-                oldstatus = status
-                sink.write(status)
-        except (KeyboardInterrupt, SystemExit):
-            raise
-        except Exception as e:
-            print("Error:" + str(e))
-            sink.write("...oops...error...")
-            sink.write(str(e))
-        sleep(interval)
-
-
 def main():
     source = TwitterTimeline()
     sink = PiLiteBoard()
     print("ready")
     sink.write("ready  ")
-    poll_for_updates(source, sink)
+    poll_for_updates(source, sink, repeat=False)
 
 
 if __name__ == "__main__":

Python_Examples/PiLiteWeather.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+import urllib
+
+from PiLiteLib import PiLiteBoard, poll_for_updates, JSONPoll
+
+
+class WeatherPoll(JSONPoll):
+    def __init__(self, location, message_format=""):
+        default_format = "{name}: {weather[0][description]}, {main[temp_c]:.0f}C"
+	base_url = "http://api.openweathermap.org/data/2.5/weather?q=%s"
+	super(WeatherPoll, self).__init__(base_url%location,
+                                          message_format or default_format)
+
+    def mung_data(self,data):
+        """ Convert local temperature from K to C"""
+        data['main']['temp_c'] = data['main']['temp']-273.15
+        return super(WeatherPoll, self).mung_data(data)
+
+
+
+def main():
+    source = WeatherPoll("London,uk")
+    sink = PiLiteBoard()
+    print("ready")
+    sink.write("ready  ")
+    poll_for_updates(source, sink)
+
+
+if __name__ == "__main__":
+    main()

Python_Examples/PiLiteWorldTime.py

@@ -1,9 +1,7 @@
 #!/usr/bin/env python
-from collections import deque
-
 import arrow
 
-from PiLiteTwitter import PiLiteBoard, poll_for_updates
+from PiLiteLib import PiLiteBoard, poll_for_updates, CyclingSources
 
 
 class WorldTime(object):
@@ -15,19 +13,6 @@ def message(self):
        now = arrow.utcnow().to(self.timezone)
        return "{} : {}".format(self.label, now.format("HH:mm:ss"))
 
-
-class CyclingSources(object):
-    def __init__(self, *sources):
-        self.sources = deque(sources)
-
-    def message(self):
-        message = self.sources[0].message()
-        self.sources.rotate(-1)
-        return message
-
-    def __len__(self):
-        return len(self.sources)
-
 
 def main():
     source = CyclingSources(WorldTime("London", "Europe/London"),

Python_Examples/PiLiteXively.py

@@ -17,8 +17,8 @@ def __init__(self, feed):
 
     def message(self):
         feed = self.api.feeds.get(self.feedid)
-        value = feed.datastreams[0].current_value
-        return "%s"%value
+        stream = feed.datastreams[0]
+        return "%s %s %s %s"%(feed.title, stream.id, stream.current_value, stream.unit.label)
 
 
 def main():