qcodes.extensions

The extensions module contains smaller modules that extend the functionality of QCoDeS. These modules may import from all of QCoDeS but do not themselves get imported into QCoDeS.

Classes:

DriverTestCase([methodName])	Create an instance of the class that will use the named test method when executed.
InferAttrs()	Holds a global set of attribute name that will be inferred

Exceptions:

InferError

Functions:

get_chain_links_of_type(link_param_type, ...)	Gets all parameters in a chain of linked parameters that match a given type
get_instrument_from_param(param)	Return the instrument attribute from a parameter
get_parameter_chain(param_chain[, ...])	Return the chain of DelegateParameters or other linking Parameters
get_parent_instruments_from_chain_of_type(...)	Gets all parent instruments in a chain of linked parameters that match a given type
get_root_parameter(param[, alt_source_attrs])	Return the root parameter in a chain of DelegateParameters or other linking Parameters
get_sole_chain_link_of_type(link_param_type, ...)	Gets the one parameter in a chain of linked parameters that matches a given type
get_sole_parent_instrument_from_chain_of_type(...)	Gets the one parent instruments in a chain of linked parameters that match a given type
infer_channel(param[, alt_source_attrs])	An alias for infer_instrument_module
infer_instrument(param[, alt_source_attrs])	Find the instrument that owns a parameter or delegate parameter.
infer_instrument_module(param[, ...])	Find the instrument module that owns a parameter or delegate parameter
log_dataset_export_info(path, **kwargs)
register_station_schema_with_vscode()	This function registers the qcodes station schema with vscode.

class qcodes.extensions.DriverTestCase(methodName='runTest')

Bases: TestCase

Create an instance of the class that will use the named test method when executed. Raises a ValueError if the instance does not have a method with the specified name.

Attributes:

driver
instrument
longMessage
maxDiff

Methods:

setUpClass()	Hook method for setting up class fixture before running tests in the class.
addClassCleanup(function, /, *args, **kwargs)	Same as addCleanup, except the cleanup items are called even if setUpClass fails (unlike tearDownClass).
addCleanup(function, /, *args, **kwargs)	Add a function, with arguments, to be called when the test is completed.
addTypeEqualityFunc(typeobj, function)	Add a type specific assertEqual style function to compare a type.
assertAlmostEqual(first, second[, places, ...])	Fail if the two objects are unequal as determined by their difference rounded to the given number of decimal places (default 7) and comparing to zero, or by comparing that the difference between the two objects is more than the given delta.
assertAlmostEquals(**kwargs)
assertCountEqual(first, second[, msg])	Asserts that two iterables have the same elements, the same number of times, without regard to order.
assertDictContainsSubset(subset, dictionary)	Checks whether dictionary is a superset of subset.
assertDictEqual(d1, d2[, msg])
assertEqual(first, second[, msg])	Fail if the two objects are unequal as determined by the '==' operator.
assertEquals(**kwargs)
assertFalse(expr[, msg])	Check that the expression is false.
assertGreater(a, b[, msg])	Just like self.assertTrue(a > b), but with a nicer default message.
assertGreaterEqual(a, b[, msg])	Just like self.assertTrue(a >= b), but with a nicer default message.
assertIn(member, container[, msg])	Just like self.assertTrue(a in b), but with a nicer default message.
assertIs(expr1, expr2[, msg])	Just like self.assertTrue(a is b), but with a nicer default message.
assertIsInstance(obj, cls[, msg])	Same as self.assertTrue(isinstance(obj, cls)), with a nicer default message.
assertIsNone(obj[, msg])	Same as self.assertTrue(obj is None), with a nicer default message.
assertIsNot(expr1, expr2[, msg])	Just like self.assertTrue(a is not b), but with a nicer default message.
assertIsNotNone(obj[, msg])	Included for symmetry with assertIsNone.
assertLess(a, b[, msg])	Just like self.assertTrue(a < b), but with a nicer default message.
assertLessEqual(a, b[, msg])	Just like self.assertTrue(a <= b), but with a nicer default message.
assertListEqual(list1, list2[, msg])	A list-specific equality assertion.
assertLogs([logger, level])	Fail unless a log message of level level or higher is emitted on logger_name or its children.
assertMultiLineEqual(first, second[, msg])	Assert that two multi-line strings are equal.
assertNoLogs([logger, level])	Fail unless no log messages of level level or higher are emitted on logger_name or its children.
assertNotAlmostEqual(first, second[, ...])	Fail if the two objects are equal as determined by their difference rounded to the given number of decimal places (default 7) and comparing to zero, or by comparing that the difference between the two objects is less than the given delta.
assertNotAlmostEquals(**kwargs)
assertNotEqual(first, second[, msg])	Fail if the two objects are equal as determined by the '!=' operator.
assertNotEquals(**kwargs)
assertNotIn(member, container[, msg])	Just like self.assertTrue(a not in b), but with a nicer default message.
assertNotIsInstance(obj, cls[, msg])	Included for symmetry with assertIsInstance.
assertNotRegex(text, unexpected_regex[, msg])	Fail the test if the text matches the regular expression.
assertNotRegexpMatches(**kwargs)
assertRaises(expected_exception, *args, **kwargs)	Fail unless an exception of class expected_exception is raised by the callable when invoked with specified positional and keyword arguments.
assertRaisesRegex(expected_exception, ...)	Asserts that the message in a raised exception matches a regex.
assertRaisesRegexp(**kwargs)
assertRegex(text, expected_regex[, msg])	Fail the test unless the text matches the regular expression.
assertRegexpMatches(**kwargs)
assertSequenceEqual(seq1, seq2[, msg, seq_type])	An equality assertion for ordered sequences (like lists and tuples).
assertSetEqual(set1, set2[, msg])	A set-specific equality assertion.
assertTrue(expr[, msg])	Check that the expression is true.
assertTupleEqual(tuple1, tuple2[, msg])	A tuple-specific equality assertion.
assertWarns(expected_warning, *args, **kwargs)	Fail unless a warning of class warnClass is triggered by the callable when invoked with specified positional and keyword arguments.
assertWarnsRegex(expected_warning, ...)	Asserts that the message in a triggered warning matches a regexp.
assert_(**kwargs)
countTestCases()
debug()	Run the test without collecting errors in a TestResult
defaultTestResult()
doClassCleanups()	Execute all class cleanup functions.
doCleanups()	Execute all cleanup functions.
enterClassContext(cm)	Same as enterContext, but class-wide.
enterContext(cm)	Enters the supplied context manager.
fail([msg])	Fail immediately, with the given message.
failIf(**kwargs)
failIfAlmostEqual(**kwargs)
failIfEqual(**kwargs)
failUnless(**kwargs)
failUnlessAlmostEqual(**kwargs)
failUnlessEqual(**kwargs)
failUnlessRaises(**kwargs)
id()
run([result])
setUp()	Hook method for setting up the test fixture before exercising it.
shortDescription()	Returns a one-line description of the test, or None if no description has been provided.
skipTest(reason)	Skip this test.
subTest([msg])	Return a context manager that will return the enclosed block of code in a subtest identified by the optional message and keyword parameters.
tearDown()	Hook method for deconstructing the test fixture after testing it.
tearDownClass()	Hook method for deconstructing the class fixture after running all tests in the class.

Miscellaneous:

failureException

alias of AssertionError

driver: type[Instrument] | None = None

instrument: Instrument

classmethod setUpClass() → None

Hook method for setting up class fixture before running tests in the class.

classmethod addClassCleanup(function, /, *args, **kwargs)

Same as addCleanup, except the cleanup items are called even if setUpClass fails (unlike tearDownClass).

addCleanup(function, /, *args, **kwargs)

Add a function, with arguments, to be called when the test is completed. Functions added are called on a LIFO basis and are called after tearDown on test failure or success.

Cleanup items are called even if setUp fails (unlike tearDown).

addTypeEqualityFunc(typeobj, function)

Add a type specific assertEqual style function to compare a type.

This method is for use by TestCase subclasses that need to register their own type equality functions to provide nicer error messages.

Parameters:

• typeobj – The data type to call this function on when both values are of the same type in assertEqual().

• function – The callable taking two arguments and an optional msg= argument that raises self.failureException with a useful error message when the two arguments are not equal.

assertAlmostEqual(first, second, places=None, msg=None, delta=None)

Fail if the two objects are unequal as determined by their difference rounded to the given number of decimal places (default 7) and comparing to zero, or by comparing that the difference between the two objects is more than the given delta.

Note that decimal places (from zero) are usually not the same as significant digits (measured from the most significant digit).

If the two objects compare equal then they will automatically compare almost equal.

assertAlmostEquals(**kwargs)

assertCountEqual(first, second, msg=None)

Asserts that two iterables have the same elements, the same number of times, without regard to order.

self.assertEqual(Counter(list(first)),

Counter(list(second)))

Example:

• [0, 1, 1] and [1, 0, 1] compare equal.

• [0, 0, 1] and [0, 1] compare unequal.

assertDictContainsSubset(subset, dictionary, msg=None)

Checks whether dictionary is a superset of subset.

assertDictEqual(d1, d2, msg=None)

assertEqual(first, second, msg=None)

Fail if the two objects are unequal as determined by the ‘==’ operator.

assertEquals(**kwargs)

assertFalse(expr, msg=None)

Check that the expression is false.

assertGreater(a, b, msg=None)

Just like self.assertTrue(a > b), but with a nicer default message.

assertGreaterEqual(a, b, msg=None)

Just like self.assertTrue(a >= b), but with a nicer default message.

assertIn(member, container, msg=None)

Just like self.assertTrue(a in b), but with a nicer default message.

assertIs(expr1, expr2, msg=None)

Just like self.assertTrue(a is b), but with a nicer default message.

assertIsInstance(obj, cls, msg=None)

Same as self.assertTrue(isinstance(obj, cls)), with a nicer default message.

assertIsNone(obj, msg=None)

Same as self.assertTrue(obj is None), with a nicer default message.

assertIsNot(expr1, expr2, msg=None)

Just like self.assertTrue(a is not b), but with a nicer default message.

assertIsNotNone(obj, msg=None)

Included for symmetry with assertIsNone.

assertLess(a, b, msg=None)

Just like self.assertTrue(a < b), but with a nicer default message.

assertLessEqual(a, b, msg=None)

Just like self.assertTrue(a <= b), but with a nicer default message.

assertListEqual(list1, list2, msg=None)

A list-specific equality assertion.

Parameters:

• list1 – The first list to compare.

• list2 – The second list to compare.

• msg – Optional message to use on failure instead of a list of differences.

assertLogs(logger=None, level=None)

Fail unless a log message of level level or higher is emitted on logger_name or its children. If omitted, level defaults to INFO and logger defaults to the root logger.

This method must be used as a context manager, and will yield a recording object with two attributes: output and records. At the end of the context manager, the output attribute will be a list of the matching formatted log messages and the records attribute will be a list of the corresponding LogRecord objects.

Example:

with self.assertLogs('foo', level='INFO') as cm:
    logging.getLogger('foo').info('first message')
    logging.getLogger('foo.bar').error('second message')
self.assertEqual(cm.output, ['INFO:foo:first message',
                             'ERROR:foo.bar:second message'])

assertMultiLineEqual(first, second, msg=None)

Assert that two multi-line strings are equal.

assertNoLogs(logger=None, level=None)

Fail unless no log messages of level level or higher are emitted on logger_name or its children.

This method must be used as a context manager.

assertNotAlmostEqual(first, second, places=None, msg=None, delta=None)

Fail if the two objects are equal as determined by their difference rounded to the given number of decimal places (default 7) and comparing to zero, or by comparing that the difference between the two objects is less than the given delta.

Note that decimal places (from zero) are usually not the same as significant digits (measured from the most significant digit).

Objects that are equal automatically fail.

assertNotAlmostEquals(**kwargs)

assertNotEqual(first, second, msg=None)

Fail if the two objects are equal as determined by the ‘!=’ operator.

assertNotEquals(**kwargs)

assertNotIn(member, container, msg=None)

Just like self.assertTrue(a not in b), but with a nicer default message.

assertNotIsInstance(obj, cls, msg=None)

Included for symmetry with assertIsInstance.

assertNotRegex(text, unexpected_regex, msg=None)

Fail the test if the text matches the regular expression.

assertNotRegexpMatches(**kwargs)

assertRaises(expected_exception, *args, **kwargs)

Fail unless an exception of class expected_exception is raised by the callable when invoked with specified positional and keyword arguments. If a different type of exception is raised, it will not be caught, and the test case will be deemed to have suffered an error, exactly as for an unexpected exception.

If called with the callable and arguments omitted, will return a context object used like this:

with self.assertRaises(SomeException):
    do_something()

An optional keyword argument ‘msg’ can be provided when assertRaises is used as a context object.

The context manager keeps a reference to the exception as the ‘exception’ attribute. This allows you to inspect the exception after the assertion:

with self.assertRaises(SomeException) as cm:
    do_something()
the_exception = cm.exception
self.assertEqual(the_exception.error_code, 3)

assertRaisesRegex(expected_exception, expected_regex, *args, **kwargs)

Asserts that the message in a raised exception matches a regex.

Parameters:

• expected_exception – Exception class expected to be raised.

• expected_regex – Regex (re.Pattern object or string) expected to be found in error message.

• args – Function to be called and extra positional args.

• kwargs – Extra kwargs.

• msg – Optional message used in case of failure. Can only be used when assertRaisesRegex is used as a context manager.

assertRaisesRegexp(**kwargs)

assertRegex(text, expected_regex, msg=None)

Fail the test unless the text matches the regular expression.

assertRegexpMatches(**kwargs)

assertSequenceEqual(seq1, seq2, msg=None, seq_type=None)

An equality assertion for ordered sequences (like lists and tuples).

For the purposes of this function, a valid ordered sequence type is one which can be indexed, has a length, and has an equality operator.

Parameters:

• seq1 – The first sequence to compare.

• seq2 – The second sequence to compare.

• seq_type – The expected datatype of the sequences, or None if no datatype should be enforced.

• msg – Optional message to use on failure instead of a list of differences.

assertSetEqual(set1, set2, msg=None)

A set-specific equality assertion.

Parameters:

• set1 – The first set to compare.

• set2 – The second set to compare.

• msg – Optional message to use on failure instead of a list of differences.

assertSetEqual uses ducktyping to support different types of sets, and is optimized for sets specifically (parameters must support a difference method).

assertTrue(expr, msg=None)

Check that the expression is true.

assertTupleEqual(tuple1, tuple2, msg=None)

A tuple-specific equality assertion.

Parameters:

• tuple1 – The first tuple to compare.

• tuple2 – The second tuple to compare.

• msg – Optional message to use on failure instead of a list of differences.

assertWarns(expected_warning, *args, **kwargs)

Fail unless a warning of class warnClass is triggered by the callable when invoked with specified positional and keyword arguments. If a different type of warning is triggered, it will not be handled: depending on the other warning filtering rules in effect, it might be silenced, printed out, or raised as an exception.

If called with the callable and arguments omitted, will return a context object used like this:

with self.assertWarns(SomeWarning):
    do_something()

An optional keyword argument ‘msg’ can be provided when assertWarns is used as a context object.

The context manager keeps a reference to the first matching warning as the ‘warning’ attribute; similarly, the ‘filename’ and ‘lineno’ attributes give you information about the line of Python code from which the warning was triggered. This allows you to inspect the warning after the assertion:

with self.assertWarns(SomeWarning) as cm:
    do_something()
the_warning = cm.warning
self.assertEqual(the_warning.some_attribute, 147)

assertWarnsRegex(expected_warning, expected_regex, *args, **kwargs)

Asserts that the message in a triggered warning matches a regexp. Basic functioning is similar to assertWarns() with the addition that only warnings whose messages also match the regular expression are considered successful matches.

Parameters:

• expected_warning – Warning class expected to be triggered.

• expected_regex – Regex (re.Pattern object or string) expected to be found in error message.

• args – Function to be called and extra positional args.

• kwargs – Extra kwargs.

• msg – Optional message used in case of failure. Can only be used when assertWarnsRegex is used as a context manager.

assert_(**kwargs)

countTestCases()

debug()

Run the test without collecting errors in a TestResult

defaultTestResult()

classmethod doClassCleanups()

Execute all class cleanup functions. Normally called for you after tearDownClass.

doCleanups()

Execute all cleanup functions. Normally called for you after tearDown.

classmethod enterClassContext(cm)

Same as enterContext, but class-wide.

enterContext(cm)

Enters the supplied context manager.

If successful, also adds its __exit__ method as a cleanup function and returns the result of the __enter__ method.

fail(msg=None)

Fail immediately, with the given message.

failIf(**kwargs)

failIfAlmostEqual(**kwargs)

failIfEqual(**kwargs)

failUnless(**kwargs)

failUnlessAlmostEqual(**kwargs)

failUnlessEqual(**kwargs)

failUnlessRaises(**kwargs)

failureException

alias of AssertionError

id()

longMessage = True

maxDiff = 640

run(result=None)

setUp()

Hook method for setting up the test fixture before exercising it.

shortDescription()

Returns a one-line description of the test, or None if no description has been provided.

The default implementation of this method returns the first line of the specified test method’s docstring.

skipTest(reason)

Skip this test.

subTest(msg=<object object>, **params)

Return a context manager that will return the enclosed block of code in a subtest identified by the optional message and keyword parameters. A failure in the subtest marks the test case as failed but resumes execution at the end of the enclosed block, allowing further test code to be executed.

tearDown()

Hook method for deconstructing the test fixture after testing it.

classmethod tearDownClass()

Hook method for deconstructing the class fixture after running all tests in the class.

class qcodes.extensions.InferAttrs

Bases: object

Holds a global set of attribute name that will be inferred

Methods:

add(attrs)
known_attrs()
discard(attr)
clear()

classmethod add(attrs: str | Iterable[str]) → None

classmethod known_attrs() → tuple[str, ...]

classmethod discard(attr: str) → None

classmethod clear() → None

exception qcodes.extensions.InferError

Bases: AttributeError

Methods:

add_note	Exception.add_note(note) -- add a note to the exception
with_traceback	Exception.with_traceback(tb) -- set self.__traceback__ to tb and return self.

Attributes:

args
name	attribute name
obj	object

add_note()

Exception.add_note(note) – add a note to the exception

args

name

attribute name

obj

object

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

qcodes.extensions.get_chain_links_of_type(link_param_type: type[C] | tuple[type[C], ...], parameter: Parameter) → tuple[C, ...]

Gets all parameters in a chain of linked parameters that match a given type

qcodes.extensions.get_instrument_from_param(param: Parameter) → InstrumentBase

Return the instrument attribute from a parameter

Parameters:

param – The parameter to get the instrument module from

Raises:

InferError – If the parameter does not have an instrument

qcodes.extensions.get_parameter_chain(param_chain: Parameter | Sequence[Parameter], alt_source_attrs: str | Sequence[str] | None = None) → tuple[Parameter, ...]

Return the chain of DelegateParameters or other linking Parameters

This method traverses singly-linked parameters and returns the resulting chain If the parameters loop, then the first and last linking parameters in the chain will be identical. Otherwise, the chain starts with the initial argument passed and ends when the chain terminates in either a non-linking parameter or a linking parameter that links to None

The search prioritizes the source attribute of DelegateParameters first, and then looks for other linking attributes in undetermined order.

Parameters:

• param_chain – The initial linking parameter or a List linking parameters from which to return the chain

• alt_source_attrs – The attribute names for custom linking parameters

qcodes.extensions.get_parent_instruments_from_chain_of_type(instrument_type: type[TInstrument] | tuple[type[TInstrument], ...], parameter: Parameter) → tuple[TInstrument, ...]

Gets all parent instruments in a chain of linked parameters that match a given type

qcodes.extensions.get_root_parameter(param: Parameter, alt_source_attrs: Sequence[str] | None = None) → Parameter

Return the root parameter in a chain of DelegateParameters or other linking Parameters

This method calls get_parameter_chain and then checks for various error conditions :param param: The DelegateParameter or other linking parameter to find the root parameter from :param alt_source_attrs: The attribute names for custom linking parameters

Raises:

• InferError – If the linking parameters do not end with a non-linking parameter

• InferError – If the chain of linking parameters loops on itself

qcodes.extensions.get_sole_chain_link_of_type(link_param_type: type[C] | tuple[type[C], ...], parameter: Parameter) → C

Gets the one parameter in a chain of linked parameters that matches a given type

qcodes.extensions.get_sole_parent_instrument_from_chain_of_type(instrument_type: type[TInstrument] | tuple[type[TInstrument], ...], parameter: Parameter) → TInstrument

Gets the one parent instruments in a chain of linked parameters that match a given type

qcodes.extensions.infer_channel(param: Parameter, alt_source_attrs: Sequence[str] | None = None) → InstrumentModule

An alias for infer_instrument_module

qcodes.extensions.infer_instrument(param: Parameter, alt_source_attrs: Sequence[str] | None = None) → InstrumentBase

Find the instrument that owns a parameter or delegate parameter.

Parameters:

• param – The DelegateParameter or other linking parameter to find the instrument from

• alt_source_attrs – The attribute names for custom linking parameters

Raises:

• InferError – If the linking parameters do not end with a non-linking parameter

• InferError – If the instrument of the root parameter is None

• InferError – If the instrument of the root parameter is not an instance of Instrument

qcodes.extensions.infer_instrument_module(param: Parameter, alt_source_attrs: Sequence[str] | None = None) → InstrumentModule

Find the instrument module that owns a parameter or delegate parameter

Parameters:

• param – The DelegateParameter or other linking parameter to find the instrument module from

• alt_source_attrs – The attribute names for custom linking parameters

Raises:

• InferError – If the linking parameters do not end with a non-linking parameter

• InferError – If the instrument module of the root parameter is None

• InferError – If the instrument module of the root parameter is not an instance of InstrumentModule

qcodes.extensions.log_dataset_export_info(path: Path | None, **kwargs: Any) → None

qcodes.extensions.register_station_schema_with_vscode() → None

This function registers the qcodes station schema with vscode.

Run this function to add the user generated station schema to the list of associated schemas for the Red Hat YAML schema extension for vscode. (https://marketplace.visualstudio.com/items?itemName=redhat.vscode-yaml)

This function will effectively add an entry to yaml.schemas in the user config file of vscode, which is located under %APPDATA/Code/User/settings.json, or will be created there.

You can alternatively access this setting via File->Preferences->Settings and search for yaml.schemas.

To enable autocompletinon of QCoDeS instrument from additional packages run qcodes.station.update_config_schema.

For more information consult qcodes/docs/examples/Station.ipynb.