Channel argument is now optional for get_acquisition value

handel/interface.py

@@ -3,6 +3,7 @@
 from __future__ import absolute_import
 
 import os
+from functools import reduce
 
 import numpy
 
@@ -544,7 +545,21 @@ def get_master_channels():
 
 # Parameters
 
-def get_acquisition_value(name, channel):
+def get_acquisition_value(name, channel=None):
+    # Get values for all channels
+    if channel is None:
+        # Get all the values
+        values = [get_acquisition_value(name, channel)
+                  for channel in get_channels()]
+        # Compare the values
+        value = reduce(lambda c, x: c if c == x else None, values)
+        # Inconsistency
+        if value is None:
+            raise ValueError(
+                'The acquisition value differs from channel to channel')
+        # Return
+        return value
+    # Get value for a single channel
     name = to_bytes(name)
     pointer = ffi.new('double *')
     code = handel.xiaGetAcquisitionValues(channel, name, pointer)
@@ -573,8 +588,7 @@ def apply_acquisition_values(channel=None):
     # Apply all
     if channel is None:
         # Only one apply operation by module is required
-        grouped = get_grouped_channels()
-        for master in map(max, grouped):
+        for master in get_master_channels():
             apply_acquisition_values(master)
         return
     # Apply single

tests/test_interface.py

@@ -895,6 +895,7 @@ def test_get_acquistion_value(interface):
         c[0] = 2.3
         return 0
 
+    # Single channel
     m.side_effect = side_effect
     assert interface.get_acquisition_value('test', channel=1) == 2.3
     arg = m.call_args[0][2]
@@ -902,6 +903,36 @@ def test_get_acquistion_value(interface):
     # Make sure errors have been checked
     interface.check_error.assert_called_once_with(0)
 
+    # All channels
+    m.reset_mock()
+    interface.check_error.reset_mock()
+    with mock.patch('handel.interface.get_channels') as m2:
+        m2.return_value = [0, 1, 2]
+        assert interface.get_acquisition_value('test') == 2.3
+    arg = m.call_args[0][2]
+    m.assert_called_with(2, b'test', arg)
+    m2.assert_called_once_with()
+    # Make sure errors have been checked
+    interface.check_error.assert_called_with(0)
+
+    def side_effect(a, b, c):
+        c[0] = a  # Channel number
+        return 0
+
+    # All channels with error
+    m.reset_mock()
+    interface.check_error.reset_mock()
+    m.side_effect = side_effect
+    with mock.patch('handel.interface.get_channels') as m2:
+        m2.return_value = [0, 1, 2]
+        with pytest.raises(ValueError):
+            interface.get_acquisition_value('test')
+    arg = m.call_args[0][2]
+    m.assert_called_with(2, b'test', arg)
+    m2.assert_called_once_with()
+    # Make sure errors have been checked
+    interface.check_error.assert_called_with(0)
+
 
 def test_set_acquisition_value(interface):
     m = interface.handel.xiaSetAcquisitionValues