Merge pull request #33 from ralph-group/dev/validators

Validator implementation for Instrument.control

docs/conf.py

@@ -63,9 +63,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = '0.3'
+version = '0.4'
 # The full version, including alpha/beta/rc tags.
-release = '0.3'
+release = '0.4'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

pymeasure/__init__.py

@@ -22,4 +22,4 @@
 # THE SOFTWARE.
 #
 
-__version__ = '0.3'
+__version__ = '0.4'

pymeasure/adapters/adapter.py

@@ -23,6 +23,7 @@
 #
 
 import numpy as np
+from copy import copy
 
 
 class Adapter(object):
@@ -58,15 +59,23 @@ def read(self):
         """
         raise NameError("Adapter (sub)class has not implemented reading")
 
-    def values(self, command):
+    def values(self, command, separator=',', cast=float):
         """ Writes a command to the instrument and returns a list of formatted
         values from the result 
 
         :param command: SCPI command to be sent to the instrument
-        :returns: String ASCII response of the instrument
+        :param separator: A separator character to split the string into a list
+        :param cast: A type to cast the result
+        :returns: A list of the desired type, or strings where the casting fails
         """
-        raise NameError("Adapter (sub)class has not implemented the "
-                        "values method")
+        results = str(self.ask(command)).strip()
+        results = results.split(separator)
+        for i, result in enumerate(results):
+            try:
+                results[i] = cast(result)
+            except:
+                pass # Keep as string
+        return results
 
     def binary_values(self, command, header_bytes=0, dtype=np.float32):
         """ Returns a numpy array from a query for binary data 
@@ -81,28 +90,38 @@ def binary_values(self, command, header_bytes=0, dtype=np.float32):
 
 
 class FakeAdapter(Adapter):
-    """The Fake adapter class is provided for debugging purposes,
-    which returns valid data for each Adapter method"""
+    """Provides a fake adapter for debugging purposes,
+    which bounces back the command so that arbitrary values 
+    testing is possible.
 
-    def read(self):
-        """ Returns a fake string for debugging purposes
-        """
-        return "Fake string!"
+    .. code-block:: python
 
-    def write(self, command):
-        """ Fakes the writing of a command for debugging purposes
-        """
-        pass
+        a = FakeAdapter()
+        assert a.read() == ""
+        a.write("5")
+        assert a.read() == "5"
+        assert a.read() == ""
+        assert a.ask("10") == "10"
+        assert a.values("10") == [10]
 
-    def values(self, command):
-        """ Returns a list of fake values for debugging purposes
+    """
+
+    _buffer = ""
+
+    def read(self):
+        """ Returns the last commands given after the
+        last read call.
         """
-        return [1.0, 2.0, 3.0]
+        result = copy(self._buffer)
+        # Reset the buffer
+        self._buffer = ""
+        return result
 
-    def binary_values(self, command, header_bytes=0, dtype=np.float32):
-        """ Returns a list of fake values in a NumPy array
+    def write(self, command):
+        """ Writes the command to a buffer, so that it can
+        be read back.
         """
-        return np.array([2, 3, 7, 8, 1], dtype=dtype)
+        self._buffer += command
 
     def __repr__(self):
         return "<FakeAdapter>"

pymeasure/adapters/serial.py

@@ -59,22 +59,6 @@ def read(self):
         """
         return b"\n".join(self.connection.readlines()).decode()
 
-    def values(self, command):
-        """ Writes a command to the instrument and returns a list of formatted
-        values from the result 
-
-        :param command: SCPI command to be sent to the instrument
-        :returns: String ASCII response of the instrument
-        """
-        results = str(self.ask(command)).strip()
-        results = results.split(',')
-        for result in results:
-            try:
-                result = float(result)
-            except:
-                pass # Keep as string
-        return results
-
     def binary_values(self, command, header_bytes=0, dtype=np.float32):
         """ Returns a numpy array from a query for binary data 
 

pymeasure/adapters/tests/test_adapter.py

@@ -0,0 +1,34 @@
+#
+# This file is part of the PyMeasure package.
+#
+# Copyright (c) 2013-2016 PyMeasure Developers
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+
+from pymeasure.adapters import FakeAdapter
+
+
+def test_adapter_values():
+    a = FakeAdapter()
+    assert a.values("5,6,7") == [5, 6, 7]
+    assert a.values("5,6,7", cast=str) == ['5', '6', '7']
+    assert a.values("X,Y,Z") == ['X', 'Y', 'Z']
+    assert a.values("X,Y,Z", cast=str) == ['X', 'Y', 'Z']
+    assert a.values("X.Y.Z", separator='.') == ['X', 'Y', 'Z']

pymeasure/adapters/visa.py

@@ -86,26 +86,6 @@ def read(self):
         :returns: String ASCII response of the instrument.
         """
         return self.connection.read()
-
-    def values(self, command, separator = ','):
-        """ Writes a command to the instrument and returns a list of numerical
-        values from the result.
-
-        :param command: SCPI command to be sent to the instrument.
-        :returns: A list of numerical values.
-        """
-        results = str(self.ask(command)).strip()
-        results = results.split(separator)
-
-        def try_float(num):
-            """ Try to convert to float """
-            try:
-                num = float(num)
-            except:
-                pass # Keep as string
-            return num
-
-        return [try_float(result) for result in results]
 
     def binary_values(self, command, header_bytes=0, dtype=np.float32):
         """ Returns a numpy array from a query for binary data 

pymeasure/instruments/danfysik/danfysik8500.py

@@ -53,6 +53,10 @@ class Danfysik8500(Instrument):
     The device will be accessible through the port :code:`/dev/danfysik`.
     """
 
+    id = Instrument.measurement(
+        "PRINT", """ Reads the idenfitication information. """
+    )
+
     def __init__(self, port):
         super(Danfysik8500, self).__init__(
             DanfysikAdapter(port),
@@ -62,12 +66,6 @@ def __init__(self, port):
         self.write("ERRT")  # Use text error messages
         self.write("UNLOCK")  # Unlock from remote or local mode
 
-    @property
-    def id(self):
-        """ The identification of the instrument.
-        """
-        return self.ask("PRINT")
-
     def local(self):
         """ Sets the instrument in local mode, where the front
         panel can be used.
@@ -93,7 +91,7 @@ def polarity(self, value):
         polarity = "+" if value > 0 else "-"
         self.write("PO %s" % polarity)
 
-    def resetInterlocks(self):
+    def reset_interlocks(self):
         """ Resets the instrument interlocks.
         """
         self.write("RS")
@@ -108,7 +106,7 @@ def disable(self):
         """
         self.write("F")
 
-    def isEnabled(self):
+    def is_enabled(self):
         """ Returns True if the current supply is enabled.
         """
         return self.status_hex & 0x800000 == 0

pymeasure/instruments/fwbell/fwbell5080.py

@@ -23,6 +23,7 @@
 #
 
 from pymeasure.instruments import Instrument, RangeException
+from pymeasure.instruments.validators import truncated_discrete_set
 from pymeasure.adapters import SerialAdapter
 from numpy import array, float64
 
@@ -35,17 +36,42 @@ class FWBell5080(Instrument):
     :param port: The serial port of the instrument
     """
 
+    id = Instrument.measurement(
+        "*IDN?", """ Reads the idenfitication information. """
+    )
+    units = Instrument.measurement(
+        ":UNIT:FLUX?",
+        """ Reads the units being used
+        """
+    )
+    range = Instrument.control(
+        ":SENS:FLUX:RANG?", ":SENS:FLUX:RANG %d",
+        """ A floating point property that controls the maximum field
+        range in Gauss, which can take the values 300, 3,000, and 
+        30,000 G. Values outside these are truncated to the closest
+        valid value. This property can be set. """,
+        validator=truncated_discrete_set,
+        values={300:0, 3000:1, 30000:2},
+        map_values=True
+    )
+
     def __init__(self, port):
         super(FWBell5080, self).__init__(
             SerialAdapter(port, 2400, timeout=0.5),
             "F.W. Bell 5080 Handheld Gaussmeter"
         )
 
-    @property
-    def id(self):
-        """ The identification of the instrument.
+    def read(self):
+        """ Overwrites the standard read method to remove the last
+        2 characters from the output
+        """
+        return super(FWBell5080, self).read()[:-2]
+
+    def ask(self):
+        """ Overwrites the standard ask method to remove the last
+        2 characters from the output
         """
-        return self.ask("*IDN?")
+        return super(FWBell5080, self).ask()[:-2]
 
     def reset(self):
         """ Resets the instrument.
@@ -60,7 +86,7 @@ def measure(self, averages=1):
         :param averages: The number of averages to preform
         """
         if averages == 1:
-            value = self.ask(":MEAS:FLUX?")[:-2]
+            value = self.ask(":MEAS:FLUX?")
             if value[-1] == "G":  # Field in gauss
                 return (float(value[:-1]), 0)
             elif value[-1] == "T":  # Field in tesla
@@ -74,52 +100,22 @@ def measure(self, averages=1):
             data = array(data, dtype=float64)
             return (data.mean(), data.std())
 
-    def set_DC_gauss_units(self):
-        """ Sets the meter to measure DC field in Gauss. """
+    def use_DC_gauss(self):
+        """ Sets the meter to measure DC fields in Gauss. """
         self.write(":UNIT:FLUX:DC:GAUS")
 
-    def set_DC_tesla_units(self):
-        """ Sets the meter to measure DC field in Tesla. """
-        self.write(":UNIT:FLUX:DC:TESL")
-
-    def set_AC_gauss_units(self):
-        """ Sets the meter to measure AC field in Gauss. """
+    def use_AC_gauss(self):
+        """ Sets the meter to measure AC fields in Gauss. """
         self.write(":UNIT:FLUX:AC:GAUS")
 
-    def set_AC_tesla_units(self):
-        """ Sets the meter to measure AC field in Telsa. """
-        self.write(":UNIT:FLUX:AC:TESL")
+    def use_DC_tesla(self):
+        """ Sets the meter to measure DC fields in Tesla. """
+        self.write(":UNIT:FLUX:DC:TESL")
 
-    def get_units(self):
-        """ Returns the units being used. """
-        return self.ask(":UNIT:FLUX?")[:-2]
+    def use_AC_tesla(self):
+        """ Sets the meter to measure AC fields in Tesla. """
+        self.write(":UNIT:FLUX:AC:TESL")
 
-    def set_auto_range(self):
+    def auto_range(self):
         """ Enables the auto range functionality. """
         self.write(":SENS:FLUX:RANG:AUTO")
-
-    def set_range(self, max_gauss):
-        """ Manually sets the range in Gauss and truncates to
-        an allowed range value
-
-        :param max_gauss: The maximum field of the range in Gauss
-        """
-        if max_gauss < 3e2:
-            self.write(":SENS:FLUX:RANG 0")
-        elif max_gauss < 3e3:
-            self.write(":SENS:FLUX:RANG 1")
-        elif max_gauss < 3e4:
-            self.write(":SENS:FLUX:RANG 2")
-        else:
-            raise RangeException("F.W. Bell 5080 is not capable of field "
-                                 "measurements above 30 kGauss")
-
-    def get_range(self):
-        """ Returns the maximum field of the range in Gauss """
-        value = int(self.ask(":SENS:FLUX:RANG?")[:-2])
-        if value == 0:
-            return 3e2
-        elif value == 1:
-            return 3e3
-        elif value == 2:
-            return 3e4