Raise minimum python version to 3.9

.github/workflows/coverage.yml

@@ -22,7 +22,7 @@ jobs:
       - uses: actions/setup-python@v5
         name: Install Python
         with:
-          python-version: '3.8'
+          python-version: '3.11'
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@stable

.github/workflows/randomized_tests.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/setup-python@v5
         name: Install Python
         with:
-          python-version: '3.8'
+          python-version: '3.11'
       - name: Install dependencies
         run: |
           python -m pip install -U pip setuptools wheel

.github/workflows/tests.yml

@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # Normally we test min and max version but we can't run python 3.8 or
+        # Normally we test min and max version but we can't run python
         # 3.9 on arm64 until actions/setup-python#808 is resolved
         python-version: ["3.10", "3.12"]
     steps:

.github/workflows/wheels.yml

@@ -41,35 +41,6 @@ jobs:
         with:
           path: ./wheelhouse/*.whl
           name: wheels-${{ matrix.os }}
-  build_wheels_macos_arm_py38:
-    name: Build wheels on macOS arm
-    runs-on: ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [macos-12]
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
-        name: Install Python
-        with:
-          python-version: '3.10'
-      - uses: dtolnay/rust-toolchain@stable
-        with:
-          components: llvm-tools-preview
-      - name: Build wheels
-        uses: pypa/cibuildwheel@v2.19.2
-        env:
-          CIBW_BEFORE_ALL: rustup target add aarch64-apple-darwin
-          CIBW_BUILD: cp38-macosx_universal2 cp38-macosx_arm64
-          CIBW_ARCHS_MACOS: arm64 universal2
-          CIBW_ENVIRONMENT: >-
-            CARGO_BUILD_TARGET="aarch64-apple-darwin"
-            PYO3_CROSS_LIB_DIR="/Library/Frameworks/Python.framework/Versions/$(python -c 'import sys; print(str(sys.version_info[0])+"."+str(sys.version_info[1]))')/lib/python$(python -c 'import sys; print(str(sys.version_info[0])+"."+str(sys.version_info[1]))')"
-      - uses: actions/upload-artifact@v4
-        with:
-          path: ./wheelhouse/*.whl
-          name: wheels-${{ matrix.os }}-arm
   build_wheels_32bit:
     name: Build wheels 32bit
     runs-on: ${{ matrix.os }}
@@ -100,7 +71,7 @@ jobs:
     environment: release
     permissions:
       id-token: write
-    needs: ["build_wheels", "build_wheels_32bit", "build_wheels_macos_arm_py38"]
+    needs: ["build_wheels", "build_wheels_32bit"]
     steps:
       - uses: actions/download-artifact@v4
         with:

Cargo.toml

@@ -34,7 +34,7 @@ rayon = "1.10"
 # distributions).  We only activate that feature when building the C extension module; we still need
 # it disabled for Rust-only tests to avoid linker errors with it not being loaded.  See
 # https://pyo3.rs/main/features#extension-module for more.
-pyo3 = { version = "0.21.2", features = ["abi3-py38"] }
+pyo3 = { version = "0.21.2", features = ["abi3-py39"] }
 
 # These are our own crates.
 qiskit-accelerate = { path = "crates/accelerate" }

asv.conf.json

@@ -17,7 +17,7 @@
     "dvcs": "git",
     "environment_type": "virtualenv",
     "show_commit_url": "http://github.com/Qiskit/qiskit/commit/",
-    "pythons": ["3.8", "3.9", "3.10", "3.11", "3.12"],
+    "pythons": ["3.9", "3.10", "3.11", "3.12"],
     "benchmark_dir": "test/benchmarks",
     "env_dir": ".asv/env",
     "results_dir": ".asv/results"

azure-pipelines.yml

@@ -37,12 +37,12 @@ parameters:
   - name: "supportedPythonVersions"
     displayName: "All supported versions of Python"
     type: object
-    default: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+    default: ["3.9", "3.10", "3.11", "3.12"]
 
   - name: "minimumPythonVersion"
     displayName: "Minimum supported version of Python"
     type: string
-    default: "3.8"
+    default: "3.9"
 
   - name: "maximumPythonVersion"
     displayName: "Maximum supported version of Python"

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "qiskit"
 description = "An open-source SDK for working with quantum computers at the level of extended quantum circuits, operators, and primitives."
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 license = {text = "Apache 2.0"}
 authors = [
     { name = "Qiskit Development Team", email = "qiskit@us.ibm.com" },
@@ -27,7 +27,6 @@ classifiers = [
     "Operating System :: Microsoft :: Windows",
     "Operating System :: POSIX :: Linux",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
@@ -140,12 +139,12 @@ include = ["qiskit", "qiskit.*"]
 
 [tool.black]
 line-length = 100
-target-version = ['py38', 'py39', 'py310', 'py311']
+target-version = ['py39', 'py310', 'py311']
 
 [tool.cibuildwheel]
 manylinux-x86_64-image = "manylinux2014"
 manylinux-i686-image = "manylinux2014"
-skip = "pp* cp36-* cp37-* *musllinux* *win32 *i686 cp38-macosx_arm64"
+skip = "pp* cp36-* cp37-* cp38-* *musllinux* *win32 *i686 cp38-macosx_arm64"
 test-skip = "*win32 *linux_i686"
 test-command = "python {project}/examples/python/stochastic_swap.py"
 # We need to use pre-built versions of Numpy and Scipy in the tests; they have a
@@ -197,7 +196,7 @@ extension-pkg-allow-list = [
     "tweedledum",
 ]
 load-plugins = ["pylint.extensions.docparams", "pylint.extensions.docstyle"]
-py-version = "3.8"  # update it when bumping minimum supported python version
+py-version = "3.9"  # update it when bumping minimum supported python version
 
 [tool.pylint.basic]
 good-names = ["a", "b", "i", "j", "k", "d", "n", "m", "ex", "v", "w", "x", "y", "z", "Run", "_", "logger", "q", "c", "r", "qr", "cr", "qc", "nd", "pi", "op", "b", "ar", "br", "p", "cp", "ax", "dt", "__unittest", "iSwapGate", "mu"]

qiskit/__init__.py

@@ -43,14 +43,6 @@
             " Qiskit unfortunately cannot enforce this requirement during environment resolution."
             " See https://qisk.it/packaging-1-0 for more detail."
         )
-if sys.version_info < (3, 9):
-    warnings.warn(
-        "Using Qiskit with Python 3.8 is deprecated as of the 1.1.0 release. "
-        "Support for running Qiskit with Python 3.8 will be removed in the "
-        "1.3.0 release, which coincides with when Python 3.8 goes end of life.",
-        DeprecationWarning,
-    )
-
 
 from . import _accelerate
 import qiskit._numpy_compat

releasenotes/notes/py3.9-min-now-c9781484a0eb288e.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    The minimum supported version of Python is now 3.9, this has been raised
+    from the previous minimum support version of 3.8. This change was necessary
+    because the upstream cPython project no longer supports Python 3.8.

test/python/circuit/test_circuit_load_from_qpy.py

@@ -1948,8 +1948,11 @@ def test_pre_v12_rejects_standalone_var(self, version):
         """Test that dumping to older QPY versions rejects standalone vars."""
         a = expr.Var.new("a", types.Bool())
         qc = QuantumCircuit(inputs=[a])
-        with io.BytesIO() as fptr, self.assertRaisesRegex(
-            UnsupportedFeatureForVersion, "version 12 is required.*realtime variables"
+        with (
+            io.BytesIO() as fptr,
+            self.assertRaisesRegex(
+                UnsupportedFeatureForVersion, "version 12 is required.*realtime variables"
+            ),
         ):
             dump(qc, fptr, version=version)
 
@@ -1959,8 +1962,9 @@ def test_pre_v12_rejects_index(self, version):
         # Be sure to use a register, since standalone vars would be rejected for other reasons.
         qc = QuantumCircuit(ClassicalRegister(2, "cr"))
         qc.store(expr.index(qc.cregs[0], 0), False)
-        with io.BytesIO() as fptr, self.assertRaisesRegex(
-            UnsupportedFeatureForVersion, "version 12 is required.*Index"
+        with (
+            io.BytesIO() as fptr,
+            self.assertRaisesRegex(UnsupportedFeatureForVersion, "version 12 is required.*Index"),
         ):
             dump(qc, fptr, version=version)
 

test/python/circuit/test_control_flow_builders.py

@@ -3464,9 +3464,12 @@ def test_switch_rejects_entering_case_after_close(self):
     def test_switch_rejects_reentering_case(self):
         """It shouldn't be possible to enter a case within another case."""
         circuit = QuantumCircuit(1, 1)
-        with circuit.switch(0) as case, case(0), self.assertRaisesRegex(
-            CircuitError, r"Cannot enter more than one case at once"
-        ), case(1):
+        with (
+            circuit.switch(0) as case,
+            case(0),
+            self.assertRaisesRegex(CircuitError, r"Cannot enter more than one case at once"),
+            case(1),
+        ):
             pass
 
     @ddt.data("1", 1.0, None, (1, 2))

test/qpy_compat/process_version.sh

@@ -45,9 +45,9 @@ if [[ ! -d qpy_$version ]] ; then
     echo "Building venv for qiskit-terra $version"
     python -m venv $version
     if [[ ${parts[0]} -eq 0 ]] ; then
-        ./$version/bin/pip install "qiskit-terra==$version"
+        ./$version/bin/pip install -c qpy_test_constraints.txt "qiskit-terra==$version"
     else
-        ./$version/bin/pip install "qiskit==$version"
+        ./$version/bin/pip install -c qpy_test_constraints.txt "qiskit==$version"
     fi
     mkdir qpy_$version
     pushd qpy_$version

test/qpy_compat/qpy_test_constraints.txt

@@ -0,0 +1,2 @@
+numpy===1.24.4
+scipy===1.10.1

test/qpy_compat/run_tests.sh

@@ -20,7 +20,7 @@ export PYTHONHASHSEED=$(python -S -c "import random; print(random.randint(1, 429
 echo "PYTHONHASHSEED=$PYTHONHASHSEED"
 
 python -m venv qiskit_venv
-qiskit_venv/bin/pip install ../..
+qiskit_venv/bin/pip install -c ../../constraints.txt ../..
 
 parallel bash ./process_version.sh ::: `git tag --sort=-creatordate`
 

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 4.0
-envlist = py38, py39, py310, py311, py312, lint-incr
+envlist = py39, py310, py311, py312, lint-incr
 isolated_build = true
 
 [testenv]
@@ -15,7 +15,7 @@ setenv =
   QISKIT_SUPRESS_PACKAGING_WARNINGS=Y
   QISKIT_TEST_CAPTURE_STREAMS=1
   QISKIT_PARALLEL=FALSE
-passenv = 
+passenv =
   RUSTUP_TOOLCHAIN
   RAYON_NUM_THREADS
   OMP_NUM_THREADS