Added open() and close() functions for more flexibility.

simple_rpc/cli.py

@@ -46,10 +46,9 @@ def rpc_list(handle, device, baudrate, wait):
     :arg int baudrate: Baud rate.
     :arg int wait: Time in seconds before communication starts.
     """
-    interface = Interface(device, baudrate, wait)
-
-    for method in interface.methods.values():
-        handle.write(_describe_method(method) + '\n\n\n')
+    with Interface(device, baudrate, wait) as interface:
+        for method in interface.methods.values():
+            handle.write(_describe_method(method) + '\n\n\n')
 
 
 def rpc_call(handle, device, baudrate, wait, name, args):
@@ -62,11 +61,11 @@ def rpc_call(handle, device, baudrate, wait, name, args):
     :arg str name: Method name.
     :arg list args: Method parameters.
     """
-    interface = Interface(device, baudrate, wait)
+    with Interface(device, baudrate, wait) as interface:
+        result = interface.call_method(name, *args)
 
-    result = interface.call_method(name, *args)
-    if result != None:
-        handle.write('{}\n'.format(result))
+        if result != None:
+            handle.write('{}\n'.format(result))
 
 
 def main():

simple_rpc/simple_rpc.py

@@ -117,29 +117,28 @@ def _parse_line(index, line):
 
 
 class Interface(object):
-    def __init__(self, device, baudrate=9600, wait=1):
+    def __init__(self, device, baudrate=9600, wait=1, autoconnect=True):
         """Initialise the class.
 
         :arg str device: Serial device name.
         :arg int baudrate: Baud rate.
         :arg int wait: Time in seconds before communication starts.
+        :arg bool autoconnect: Automatically connect.
         """
-        try:
-            self._connection = Serial(device, baudrate)
-        except SerialException as error:
-            raise IOError(error.strerror.split(':')[0])
-        sleep(wait)
+        self._device = device
+        self._wait = wait
 
-        self.methods = self._get_methods()
-        for method in self.methods.values():
-            setattr(
-                self, method['name'], MethodType(_make_function(method), self))
+        self._connection = Serial(baudrate=baudrate)
+        self.methods = {}
 
-        device_version = self.call_method('version')
-        if device_version != _version:
-            raise ValueError(
-                'version mismatch (device: {}, client: {})'.format(
-                    device_version, _version))
+        if autoconnect:
+            self.open()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
 
     def _read_str(self):
         """Read a delimited string from serial.
@@ -207,6 +206,46 @@ def _get_methods(self):
 
         return methods
 
+    def open(self):
+        """Connect to serial device."""
+        if self._connection.isOpen():
+            return
+
+        self._connection.port = self._device
+        try:
+            self._connection.open()
+        except SerialException as error:
+            raise IOError(error.strerror.split(':')[0])
+        sleep(self._wait)
+
+        self.methods = self._get_methods()
+        for method in self.methods.values():
+            setattr(
+                self, method['name'], MethodType(_make_function(method), self))
+
+        device_version = self.call_method('version')
+        if device_version != _version:
+            raise ValueError(
+                'version mismatch (device: {}, client: {})'.format(
+                    device_version, _version))
+
+    def close(self):
+        """Disconnect from serial device."""
+        if not self._connection.isOpen():
+            return
+
+        for method in self.methods:
+            delattr(self, method)
+
+        self.methods = {}
+
+        if (self._connection):
+            self._connection.close()
+
+    def is_open(self):
+        return self._connection.isOpen()
+
+
     def call_method(self, name, *args):
         """Execute a method.
 

tests/test_lib.py

@@ -2,10 +2,17 @@
 from simple_rpc.simple_rpc import _version
 
 
-_interface = Interface('/dev/ttyACM0')
+_interface = Interface('/dev/ttyACM0', autoconnect=False)
 
 
 class TestLib(object):
+    def test_open(self):
+        assert not _interface.is_open()
+        assert _interface.methods == {}
+        _interface.open()
+        assert _interface.is_open()
+        assert _interface.methods != {}
+
     def test_version(self):
         assert _interface.version() == _version
 
@@ -49,3 +56,10 @@ def test_doc_3(self):
 
     def test_doc_4(self):
         assert _interface.methods['ping']['parameters'][0]['doc'] == 'Value.'
+
+    def test_close(self):
+        assert _interface.is_open()
+        assert _interface.methods != {}
+        _interface.close()
+        assert not _interface.is_open()
+        assert _interface.methods == {}