Deprecate `qiskit.circuit.classicalfunction` #13786

gadial · 2025-02-05T10:10:06Z

Summary

This PR deprecates the ClassicalFunction class and related classical_function method, to be removed in 2.0.

Partially addresses #13755

Details and comments

ClassicalFunction is a useful class, but it relies on the tweedledum library which is dropped from qiskit in 2.0. Most of the functionality enabled by ClassicalFunction is also supplied by BooleanExpression that is made independent from tweedledum in #13769 and it's not clear if there is demand for the extra functionality at this stage.

qiskit-bot · 2025-02-05T10:10:12Z

One or more of the following people are relevant to this code:

@Qiskit/terra-core

coveralls · 2025-02-05T10:36:56Z

Pull Request Test Coverage Report for Build 13235330308

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

For more information on this, see Tracking coverage changes with pull request builds.
To avoid this issue with future PRs, see these Recommended CI Configurations.
For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

0 of 8 (0.0%) changed or added relevant lines in 3 files are covered.
1405 unchanged lines in 44 files lost coverage.
Overall coverage decreased (-0.4%) to 88.267%

Changes Missing Coverage	Changed/Added Lines	%
qiskit/circuit/classicalfunction/init.py	2	0.0%
qiskit/circuit/classicalfunction/boolean_expression.py	3	0.0%
qiskit/circuit/classicalfunction/classicalfunction.py	3	0.0%

Files with Coverage Reduction	New Missed Lines	%
crates/accelerate/src/gate_direction.rs	1	97.34%
qiskit/pulse/schedule.py	1	88.42%
qiskit/utils/parallel.py	1	80.7%
qiskit/pulse/instruction_schedule_map.py	1	95.9%
qiskit/providers/fake_provider/fake_openpulse_3q.py	1	92.86%
qiskit/transpiler/passes/scheduling/alignments/check_durations.py	1	77.78%
qiskit/circuit/classicalfunction/classicalfunction.py	1	0.0%
crates/accelerate/src/euler_one_qubit_decomposer.rs	1	91.5%
crates/accelerate/src/twirling.rs	1	97.62%
qiskit/circuit/classicalfunction/init.py	1	0.0%

Totals
Change from base Build 13154732632:	-0.4%
Covered Lines:	78616
Relevant Lines:	89066

💛 - Coveralls

Cryoris

Thanks for taking this on, I'm happy to see this cleaned up for 2.0! 🙂

It seems there is still one call to classical function in the visualization tests, which is not caught and causes the CI to fail.

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml

qiskit/circuit/classicalfunction/__init__.py

Cryoris

Some small comments, otherwise LGTM 👍🏻

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml

qiskit/circuit/classicalfunction/__init__.py

qiskit/circuit/classicalfunction/exceptions.py

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml

ShellyGarion

Just making sure: in this PR we raise deprecation warnings, and the new API will be introduced in qiskit 2.0 ?
Should there be another PR for removing ClassicalFunction for qiskit 2.0, since it's not part of #13769?

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml

ShellyGarion · 2025-02-09T16:33:40Z

I also found tweedledum here:

qiskit/qiskit/utils/optionals.py

Line 186 in 9ae0a80

.. py:data:: HAS_TWEEDLEDUM

should it be removed / deprecated?

See also this test file:
https://github.com/Qiskit/qiskit/blob/main/test/python/circuit/test_extensions_standard.py

gadial · 2025-02-10T06:36:49Z

Just making sure: in this PR we raise deprecation warnings, and the new API will be introduced in qiskit 2.0 ? Should there be another PR for removing ClassicalFunction for qiskit 2.0, since it's not part of #13769?

Yes, we'll add the new API in 2.0.

I think we can use #13769 to remove ClassicalFunction, even though I usually try to keep PR's centered around one change.

gadial · 2025-02-10T06:38:53Z

I also found tweedledum here:

qiskit/qiskit/utils/optionals.py

Line 186 in 9ae0a80

.. py:data:: HAS_TWEEDLEDUM

should it be removed / deprecated?
See also this test file: https://github.com/Qiskit/qiskit/blob/main/test/python/circuit/test_extensions_standard.py

It should definitely be removed, but I don't think we need deprecation warning here.

1ucian0 · 2025-02-10T14:46:29Z

This one should be against stable/1.4

…66.yaml Co-authored-by: Julien Gacon <gaconju@gmail.com>

Co-authored-by: Julien Gacon <gaconju@gmail.com>

…66.yaml Co-authored-by: Julien Gacon <gaconju@gmail.com>

Cryoris

This deprecation is a bit finnicky. Our deprecation rules are that

an alternative implementation must be available for 1 minor release, where no DeprecationWarning is issued (PendingDeprecationWarning is fine)
then, the DeprecationWarning must be issued for 1 minor release
finally, we can remove the feature

Here we cannot point users to the BitFlipOracle, which doesn't exist yet, and we cannot issue a deprecation warning inside PhaseOracle, which doesn't have a deprecation-free alternative. In a perfect world we would have introduced a tweedledum-free version of PhaseOracle and the BitFlipOracle in 1.3 already, deprecate the classicalfunction in 1.4 and remove in 2.0.

To move forward while still being true to the deprecation policy, I'd suggest we'd

just point to PhaseOracle as alternative path for everything (this has existed for long enough)
don't issue any warnings when using PhaseOracle
tell users how they could get a boolean expression/bitflip oracle from a PhaseOracle

Cryoris · 2025-02-12T08:17:55Z

qiskit/circuit/classicalfunction/__init__.py

+@deprecate_func(
+    since="1.4",
+    removal_timeline="in Qiskit 2.0",
+    additional_msg="Use `PhaseOracle` or `BitFlipOracle` instead",


The BitFlipOracle doesn't exist in Qiskit 1.4, we need to remove mentioning it from the deprecation messages. Since the PhaseOracle is not a direct replacement of the classical functions but requires extra steps, it might be good to tell the users how to get there

Suggested change

additional_msg="Use `PhaseOracle` or `BitFlipOracle` instead",

additional_msg=(

"Use the PhaseOracle instead, which can be turned into a "

"bit-flip oracle by applying Hadamard gates on the target "

"qubit before and after the instruction."

),

Done in 4510aee

Cryoris · 2025-02-12T08:18:48Z

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml

+    is going to have a `tweedledum` independent implementation, and
+    the :class:`.BitFlipOracle` which will be added in Qiskit 2.0.


We could also add a code snippet as example if we want to be extra nice to the users 😄

I second that, and maybe the release notes would be a perfect place to include an example on how to convert the phase oracle to the bit-flip oracle.

Cryoris · 2025-02-12T08:25:50Z

test/python/circuit/library/test_phase_oracle.py

+            DeprecationWarning,
+            expected_regex="BooleanExpression`` is deprecated as of qiskit 1.4",
+        ):
+            oracle = PhaseOracle(expression)


The PhaseOracle is not getting deprecated, it should not emit a deprecation warning. Instead we can filter the warning in the PhaseOracle code in 1.4 until we get the tweedledum-free version in 2.0.

Done in 4510aee

…deprecated PhaseOracle

qiskit/circuit/classicalfunction/__init__.py

…flip oracle

ShellyGarion

LGTM. do you have any last comments @Cryoris ?

Cryoris · 2025-02-14T08:26:34Z

qiskit/circuit/library/phase_oracle.py

+        import warnings
+
+        warnings.simplefilter("ignore", DeprecationWarning)


This will enable a global filter, we should use

with warnings.catch_warnings(action="ignore", category=DeprecationWarning): # code here...

🙂

Done in b4878c6

Cryoris · 2025-02-14T08:28:04Z

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml

+
+    .. code-block:: python
+
+        phase_flip_oracle = PhaseOracle(bool_expr)


That's nice! What do you think of making this a fully executable snippet with some example boolean expression?

Done in b4878c6

Cryoris

Thanks for all the work!

* Deprecate `ClassicalFunction` * Changes according to PR review * Update releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml Co-authored-by: Julien Gacon <gaconju@gmail.com> * Update qiskit/circuit/classicalfunction/__init__.py Co-authored-by: Julien Gacon <gaconju@gmail.com> * Update releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml Co-authored-by: Julien Gacon <gaconju@gmail.com> * Test fix * Deprecate `BooleanExpression` as well * Linting * Test fix due to deprecation * Update the release note * Test message fix * Update deprecation message and ignore deprecation warning in the non-deprecated PhaseOracle * Added an explanation on how to create a bit flip oracle from a phase flip oracle * Fixes according to PR review * Typo --------- Co-authored-by: Julien Gacon <gaconju@gmail.com>

Cryoris · 2025-02-18T16:59:57Z

Third try to really be sure it's not a flake..

ElePT · 2025-02-19T11:11:04Z

I just inspected the backwards compatibility tests and found the source of the problems we are seeing:
qiskit.qpy.exceptions.QpyError: 'Incompatible symengine version 0.14 used to generate the QPY payload'. We need to see why symengine 0.14 is getting installed where it shouldn't be. [Edit: earlier qiskit versions don't have the pin on the symengine version, that's why].

gadial requested a review from a team as a code owner February 5, 2025 10:10

gadial added this to the 1.4.0 milestone Feb 5, 2025

Cryoris reviewed Feb 5, 2025

View reviewed changes

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml Outdated Show resolved Hide resolved

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml Show resolved Hide resolved

qiskit/circuit/classicalfunction/__init__.py Show resolved Hide resolved

Cryoris reviewed Feb 5, 2025

View reviewed changes

Cryoris changed the title ~~Deprecate ClassicalFunction~~ Deprecate qiskit.circuit.classicalfunction Feb 5, 2025

gadial requested a review from nonhermitian as a code owner February 6, 2025 07:53

ShellyGarion reviewed Feb 9, 2025

View reviewed changes

releasenotes/notes/deprecate-classical-function-3bf44ef26d984366.yaml Outdated Show resolved Hide resolved

gadial mentioned this pull request Feb 10, 2025

[WIP] Remove the classical_function module and all tweedledum-related code #13815

Open

gadial changed the base branch from main to stable/1.4 February 11, 2025 09:58

gadial requested review from a team, alexanderivrii, eggerdj, wshanks and jyu00 as code owners February 11, 2025 09:58

gadial and others added 10 commits February 11, 2025 12:09

Deprecate ClassicalFunction

5fa62c0

Changes according to PR review

97eeda1

Update releasenotes/notes/deprecate-classical-function-3bf44ef26d9843…

265da35

…66.yaml Co-authored-by: Julien Gacon <gaconju@gmail.com>

Update qiskit/circuit/classicalfunction/__init__.py

ecc53c3

Co-authored-by: Julien Gacon <gaconju@gmail.com>

Update releasenotes/notes/deprecate-classical-function-3bf44ef26d9843…

0776b87

…66.yaml Co-authored-by: Julien Gacon <gaconju@gmail.com>

Test fix

7c5bb6a

Deprecate BooleanExpression as well

4c255f1

Linting

07a99e3

Test fix due to deprecation

62e8346

Update the release note

09ab685

Cryoris reviewed Feb 12, 2025

View reviewed changes

Update deprecation message and ignore deprecation warning in the non-…

4510aee

…deprecated PhaseOracle

gadial dismissed ShellyGarion’s stale review via 4510aee February 12, 2025 10:09

gadial requested a review from Cryoris February 12, 2025 11:38

alexanderivrii reviewed Feb 12, 2025

View reviewed changes

qiskit/circuit/classicalfunction/__init__.py Outdated Show resolved Hide resolved

Added an explanation on how to create a bit flip oracle from a phase …

ad5cdd0

…flip oracle

ShellyGarion previously approved these changes Feb 14, 2025

View reviewed changes

Cryoris reviewed Feb 14, 2025

View reviewed changes

Fixes according to PR review

b4878c6

gadial dismissed ShellyGarion’s stale review via b4878c6 February 16, 2025 13:22

Typo

d8b8bdf

gadial requested review from Cryoris and alexanderivrii February 16, 2025 15:47

Cryoris approved these changes Feb 18, 2025

View reviewed changes

Cryoris added this pull request to the merge queue Feb 18, 2025

github-merge-queue bot removed this pull request from the merge queue due to failed status checks Feb 18, 2025

ShellyGarion added this pull request to the merge queue Feb 18, 2025

github-merge-queue bot removed this pull request from the merge queue due to failed status checks Feb 18, 2025

Cryoris added this pull request to the merge queue Feb 18, 2025

github-merge-queue bot removed this pull request from the merge queue due to failed status checks Feb 18, 2025

Merge branch 'stable/1.4' into deprecate_classical_function

3ee10b5

ElePT added this pull request to the merge queue Feb 19, 2025

github-merge-queue bot removed this pull request from the merge queue due to failed status checks Feb 19, 2025

ElePT added this pull request to the merge queue Feb 19, 2025

Merged via the queue into Qiskit:stable/1.4 with commit 71eb989 Feb 19, 2025
16 checks passed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Deprecate `qiskit.circuit.classicalfunction` #13786

Deprecate `qiskit.circuit.classicalfunction` #13786

gadial commented Feb 5, 2025

qiskit-bot commented Feb 5, 2025

coveralls commented Feb 5, 2025 •

edited

Loading

Cryoris left a comment •

edited

Loading

Cryoris left a comment

ShellyGarion left a comment •

edited

Loading

ShellyGarion commented Feb 9, 2025 •

edited

Loading

gadial commented Feb 10, 2025

gadial commented Feb 10, 2025

1ucian0 commented Feb 10, 2025

Cryoris left a comment

Cryoris Feb 12, 2025

gadial Feb 12, 2025

Cryoris Feb 12, 2025

alexanderivrii Feb 12, 2025

Cryoris Feb 12, 2025

gadial Feb 12, 2025

ShellyGarion left a comment

Cryoris Feb 14, 2025

gadial Feb 16, 2025

Cryoris Feb 14, 2025

gadial Feb 16, 2025

Cryoris left a comment

Cryoris commented Feb 18, 2025

ElePT commented Feb 19, 2025 •

edited

Loading

-    additional_msg="Use `PhaseOracle` or `BitFlipOracle` instead",
+    additional_msg=(
+        "Use the PhaseOracle instead, which can be turned into a "
+        "bit-flip oracle by applying Hadamard gates on the target "
+        "qubit before and after the instruction."
+    ),

		is going to have a `tweedledum` independent implementation, and
		the :class:`.BitFlipOracle` which will be added in Qiskit 2.0.

		import warnings

		warnings.simplefilter("ignore", DeprecationWarning)


		.. code-block:: python

		phase_flip_oracle = PhaseOracle(bool_expr)

Deprecate qiskit.circuit.classicalfunction #13786

Deprecate qiskit.circuit.classicalfunction #13786

Conversation

gadial commented Feb 5, 2025

Summary

Details and comments

qiskit-bot commented Feb 5, 2025

coveralls commented Feb 5, 2025 • edited Loading

Pull Request Test Coverage Report for Build 13235330308

Warning: This coverage report may be inaccurate.

Details

💛 - Coveralls

Cryoris left a comment • edited Loading

Choose a reason for hiding this comment

Cryoris left a comment

Choose a reason for hiding this comment

ShellyGarion left a comment • edited Loading

Choose a reason for hiding this comment

ShellyGarion commented Feb 9, 2025 • edited Loading

gadial commented Feb 10, 2025

gadial commented Feb 10, 2025

1ucian0 commented Feb 10, 2025

Cryoris left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

ShellyGarion left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Cryoris left a comment

Choose a reason for hiding this comment

Cryoris commented Feb 18, 2025

ElePT commented Feb 19, 2025 • edited Loading

Deprecate `qiskit.circuit.classicalfunction` #13786

Deprecate `qiskit.circuit.classicalfunction` #13786

coveralls commented Feb 5, 2025 •

edited

Loading

Cryoris left a comment •

edited

Loading

ShellyGarion left a comment •

edited

Loading

ShellyGarion commented Feb 9, 2025 •

edited

Loading

ElePT commented Feb 19, 2025 •

edited

Loading