improved code style

app.py

@@ -6,26 +6,34 @@ import RPi.GPIO as GPIO
 import shutil
 import os
 
+#local imports
 from xml_reader import Xml_reader
 from interface_handler import Interface_handler
 
+# setup xml_reader and interface_handler
 dir = os.path.dirname(os.path.abspath(__file__))
-xml_reader = Xml_reader(str(dir + '/XML/config.xml'),str(dir + '/XML/config.xsd'))
+xml_reader = Xml_reader(str(dir + '/XML/config.xml'),
+    str(dir + '/XML/config.xsd'))
 interface_handler = Interface_handler(xml_reader)
 
-device_names = xml_reader.get_device_names()
-
 app = FlaskAPI(__name__)
 
 @app.route('/', methods=["GET"])
 def api_root():
-    return {
+    """method for the root of the API
-           "device_url": request.url + "device/<device_name>",
+
-             "device_url_POST": {"output": "<value>"}
+    Returns:
-                 }
+        html: a welcom message
+    """
+    return "<h1>Success. You have reached the root of the APED API.</h1>"
 
 @app.route('/XML/', methods=["GET","POST"])
 def xml_transfer():
+    """method for transfering the config.xml files to and from the raspberry
+
+    Returns:
+        the config.xml or the occured errors
+    """
     try:
         #return the current config.xml
         if request.method == "GET":
@@ -40,9 +48,12 @@ def xml_transfer():
             tmp_file.write(data)
             tmp_file.close()
             #check config.xml against the XSD file
-            if xml_reader.validate('/tmp/aped_device/config.xml',str(dir + '/XML/config.xsd')):
+            if xml_reader.validate('/tmp/aped_device/config.xml',
-                shutil.move(str(dir + '/XML/config.xml'),str(dir + '/XML/config_old.xml'))
+                str(dir + '/XML/config.xsd')):
-                shutil.move('/tmp/aped_device/config.xml',str(dir + '/XML/config.xml'))
+                shutil.move(str(dir + '/XML/config.xml'),
+                    str(dir + '/XML/config_old.xml'))
+                shutil.move('/tmp/aped_device/config.xml',
+                    str(dir + '/XML/config.xml'))
                 xml_reader.set_root(str(dir + '/XML/config.xml'))
                 interface_handler.init_gpio()
             else:
@@ -51,12 +62,32 @@ def xml_transfer():
     except Exception as e:
         return {'error' : str(e)}
 
-@app.route('/device/<device_name>/', defaults={'buffering': None}, methods=["GET", "POST"])
+@app.route('/device/', methods=["GET"])
+def api_general_device_info():
+    """method to read all the available device names
+
+    Returns:
+        JSON: the available device names
+    """
+    return {"device_names": str(xml_reader.get_device_names())}
+  
+@app.route('/device/<device_name>/', defaults={'buffering': None}, 
+    methods=["GET", "POST"])
 @app.route('/device/<device_name>/<buffering>/', methods=["GET", "POST"])
 def api_devices(device_name: str, buffering: str):
+    """the method for reading and writing to and from the connected devices
+
+    Args:
+        device_name (str): the name of the relevant device
+        buffering (str): whether or not the buffer of the device is requested
+
+    Returns:
+        the relevant information about the device in JSON format
+    """
     try:
         if request.method == "POST":
-            response = interface_handler.write(device_name,request.data.get("output"))
+            response = interface_handler.write(device_name,
+                request.data.get("output"))
         if buffering == 'buffer':
             return {'buffer': interface_handler.read_buffer(device_name)}
         else:

interface_handler.py

@@ -74,7 +74,10 @@ class Interface_handler:
             port_info = self.xml_reader.get_port(device_name)
             protocol = port_info["protocol"]
             pins = port_info["pins"]
-            frequency = int(port_info["frequency"]) if port_info["frequency"] != '' else 1
+            if port_info["frequency"] != '':
+                frequency = int(port_info["frequency"]) 
+            else:
+                frequency = 1
 
             #setup pins
             for pin in pins:
@@ -87,7 +90,8 @@ class Interface_handler:
                     pwm = GPIO.PWM(self.Pin[pin].value,frequency)
                     self.pwms[self.Pin[pin].value] = pwm
                 else:
-                    raise NotImplementedError('the protocol of the device %s is not implemented' % device_name)
+                    raise NotImplementedError('the protocol of the' 
+                        + 'device %s is not implemented' % device_name)
 
     def init_buffer(self):
         """initializes the buffer thread 
@@ -123,7 +127,8 @@ class Interface_handler:
             dict: the buffer of the device
         """
         if self.xml_reader.get_port(device_name) == None:
-            raise NameError('the device with the name %s is unknown' % device_name)
+            raise NameError('the device with the name %s is unknown' 
+                % device_name)
         returnValues = dict()
         port_info = self.xml_reader.get_port(device_name)
         protocol = port_info["protocol"]
@@ -134,7 +139,8 @@ class Interface_handler:
                     pin : str(self.buffers[self.Pin[pin].value])
                 })
             else: #throw error for devices without buffer
-                raise ValueError("device %s does not have a buffer" % device_name)
+                raise ValueError("device %s does not have a buffer" 
+                    % device_name)
         return returnValues 
                 
 
@@ -153,7 +159,8 @@ class Interface_handler:
         """
         #check device_name is valid
         if self.xml_reader.get_port(device_name) == None:
-            raise NameError('the device with the name %s is unknown' % device_name)
+            raise NameError('the device with the name %s is unknown'
+                % device_name)
         returnValues = dict()
         port_info = self.xml_reader.get_port(device_name)
         protocol = port_info["protocol"]
@@ -168,7 +175,8 @@ class Interface_handler:
                     pin : str(self.pwm_dutycycles[self.Pin[pin].value])
                 })
             else: #throw error for protocols without read functionality
-                raise ValueError("you can not read from device %s" % device_name)
+                raise ValueError("you can not read from device %s" 
+                    % device_name)
         return returnValues
 
 
@@ -190,7 +198,8 @@ class Interface_handler:
 
         #check device_name is valid
         if self.xml_reader.get_port(device_name) == None:
-            raise NameError('the device with the name %s is unknown' % device_name)
+            raise NameError('the device with the name %s is unknown'
+                % device_name)
         port_info = self.xml_reader.get_port(device_name)
         protocol = port_info["protocol"]
         pins = port_info["pins"]
@@ -198,10 +207,12 @@ class Interface_handler:
         if protocol == "DO":
             #type check input value
             if not isinstance(output,dict):
-                raise TypeError("value must be a dictionary of GPIOs and values")
+                raise TypeError(
+                    "value must be a dictionary of GPIOs and values")
             for pin in output:
                 if not pin in self.xml_reader.get_port(device_name)["pins"]:
-                    raise ValueError(str("pin %s is not a part of device %s",pin,device_name))
+                    raise ValueError(str("pin %s is not a part of device %s",
+                        pin,device_name))
                 if not output[pin] in ['0','1']:
                     raise TypeError("value must be 1 or 0")
                 value = GPIO.HIGH if output[pin] == '1' else GPIO.LOW
@@ -210,14 +221,17 @@ class Interface_handler:
         #PWM write
         elif protocol == "PWM":
             if not isinstance(output,dict):
-                raise TypeError("value must be a dictionary of GPIOs and values")
+                raise TypeError(
+                    "value must be a dictionary of GPIOs and values")
             for pin in output:
                 if not pin in self.xml_reader.get_port(device_name)["pins"]:
-                    raise ValueError(str("pin %s is not a part of device %s",pin,device_name))
+                    raise ValueError(str("pin %s is not a part of device %s",
+                        pin,device_name))
                 dutycycle = int(output[pin])
                 self.pwm_dutycycles[self.Pin[pin].value] = dutycycle
                 if not dutycycle in range(0,101,1):
-                    raise TypeError("value must be a whole number between 0 and 100")
+                    raise TypeError(
+                        "value must be a whole number between 0 and 100")
                 self.pwms[self.Pin[pin].value].stop()
                 self.pwms[self.Pin[pin].value].start(dutycycle)
             return output

xml_reader.py

@@ -82,7 +82,8 @@ class Xml_reader:
             "Device[@name='%s']/Port" % device_name)
         return {
             'protocol': port.get('protocol'),
-            'frequency': port.get('frequency') if port.get('frequency') != None else '',
+            'frequency': 
+                port.get('frequency') if port.get('frequency') != None else '',
             'pins': [
                 pin.text for pin in self.root.findall(
                     "Device[@name='%s']/Port/Pin" % device_name