quantum: modernize QFT to Qiskit 2.x and re-enable its test

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.

[priya-sundaram-dev]

Describe your change:

Follow-up to #15118 and the ask in #15081. Re-opens #15119 (auto-closed by the keeper bot for the draft's unchecked template — CI has since gone fully green, so there's no reason to keep it a draft).

quantum/q_fourier_transform.py imported Aer and execute from qiskit — both removed in the Qiskit 1.0 API break — so the file could never import, which is why it sat on the --ignore list and its doctest was never validated. This ports it to the current API:

• Simulate with the pure-Python BasicSimulator (transpile() + backend.run()) instead of Aer.get_backend("qasm_simulator") + execute(). BasicSimulator ships inside qiskit core, so no compiled qiskit-aer backend is required — relevant because qiskit-aer has no Python 3.14 wheels yet (Need binary distribution on PyPI for Python 3.14 Qiskit/qiskit-aer#2378), while this repo requires Python ≥ 3.14.
• Seed the run (seed_simulator=42) and rewrite the doctest to check the reproducible, shot-noise-independent facts (all four outcomes appear; counts sum to the shot total) rather than exact per-state counts — the old {'00': 2500, ...} doctest was statistically impossible and only "passed" because it was ignored.
• Add qiskit>=2 to dependencies; drop --ignore=quantum/q_fourier_transform.py and the stale # TODO: #8818 comment from build.yml.

CI is green:build and build_docs both pass on the repo's Python 3.14 interpreter, confirming qiskit core installs/imports and the new doctest runs and passes. Closes the quantum half of #8818.

The remaining TensorFlow --ignore entries are hard-blocked by the Python 3.14 floor (TensorFlow tops out at 3.13); full matrix is in #15081 / the earlier #15119 thread.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.

[cclauss]

Thousands separators make numbers easier for humans to read.

[priya-sundaram-dev]

Thanks for the review and the merge, @cclauss! Glad the QFT test is back in the suite on Qiskit 2.x. Happy to keep chipping away at the remaining --ignore entries in build.yml — the TensorFlow/Keras files are the main blockers (no 3.14 wheels yet); I'll follow up on #15081 if a path opens up.

[cclauss]

Awesome work on Qiskit!

I find it stunning that TensorFlow/Keras does not have v3.14 wheels when v3.15 is available as a release candidate.

[priya-sundaram-dev]

Right? The catch is that a "3.15 release candidate exists" and "TF/Keras ship wheels for 3.x" are almost unrelated events. TensorFlow bundles a big C++/pybind11 extension that has to be rebuilt and tested against each new CPython ABI, so their wheels historically trail the interpreter by one or two minor versions — 3.15 RC availability just means CPython froze its ABI, not that TF has caught up on 3.14 yet.

The cleaner path for us is the pure-Python-first files: the lstm_prediction example is Keras-only today, but the same model expresses fine on a JAX backend (keras.backend = jax), and JAX does publish 3.14 wheels. Happy to spin that up as a separate PR so we can drop another --ignore without waiting on the TF release train. The genuinely TF-graph-API files (k_means_clustering_tensorflow, the old input_data) are a bigger lift and probably better rewritten than ported.

[cclauss]

I like your Keras-only workaround idea. Please go for it.