Drop support for Python 3.9 (#360)

Co-authored-by: Kento Ueda <38037695+to24toro@users.noreply.github.com>

Author: DanPuzzuoli

.github/workflows/main.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.10', '3.11', '3.12']
         os: ["ubuntu-latest", "macOS-latest", "windows-latest"]
     steps:
       - uses: actions/checkout@v2

qiskit_dynamics/arraylias/alias.py

@@ -72,9 +72,7 @@
 
 
 def _isArrayLike(x: any) -> bool:
-    """Return true if x is an ArrayLike object. Equivalent to isinstance(x, ArrayLike), which does
-    not work in Python 3.9.
-    """
+    """Return true if x is an ArrayLike object. Equivalent to isinstance(x, ArrayLike)."""
     return isinstance(x, (DYNAMICS_NUMPY_ALIAS.registered_types(), list))
 
 

releasenotes/notes/drop-3.9-068213c3b17235bd.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    Support for Python 3.9 has been dropped.

setup.py

@@ -61,7 +61,6 @@
         "Operating System :: MacOS",
         "Operating System :: POSIX :: Linux",
         "Programming Language :: Python :: 3 :: Only",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
@@ -75,7 +74,7 @@
     },
     install_requires=requirements,
     include_package_data=True,
-    python_requires=">=3.9",
+    python_requires=">=3.10",
     extras_require={
         "jax": jax_extras
     },