Merge pull request #131 from lcmd-epfl/drop-py39

Drop python 3.9 support

Author: briling

README.md

@@ -34,6 +34,7 @@ The last one is recommended if you do not know which features you wish to use, s
 | `[equio]`   | interface with [metatensor](https://github.com/metatensor/metatensor) |
 | `[regression]` | tools to run kernel ridge regression (no quantum chemistry) | 
 | `[wigner]` | tool to compute Wigner d-matrices for real spherical harmonics |
+| `[dev]` | all above + linting + documentation building |
 
 
 If you want to be able to edit Q-stack's code after installing, you need to download it yourself, for instance with this series of commands
@@ -43,7 +44,7 @@ git clone https://github.com/lcmd-epfl/Q-stack
 cd Q-stack
 
 #optionally, run the following line, if you want to be extra-careful about reproducibility, by installing a well-known version of all dependencies
-python -m pip install -r requirements.py3.13.txt   # (or "requirements.py3.{9,11}.txt" if you have an older version of python and that first file doesn't work)
+python -m pip install -r requirements.py3.13.txt   # (or "requirements.py3.11.txt" if you have an older version of python and that first file doesn't work)
 
 python -m pip install -e .[all]    # note: this translates as "install as '-e'ditable, install from this directory ('.'), with optional feature 'all'"
 ```

pyproject.toml

@@ -35,7 +35,7 @@ classifiers = [
 
 # note: minimal versions were just copy-pasted from requirements.txt, some earlier versions may also work
 # note: maximal versions are just the latest versions to exist when compatibility checks were made, later versions may also work
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     'numpy >= 1.26.1, < 2.4',
     'scipy >= 1.1.0, < 1.17',

qstack/__init__.py

@@ -1,17 +1,5 @@
 """Q-stack."""
 
-import sys
-import warnings
-import builtins
 from qstack import tools
 from qstack import constants
 from qstack import mathutils
-
-
-if sys.version_info[1]<10:
-    warnings.warn('Redefining built-in function zip for compatibility', stacklevel=1)
-    _zip = builtins.zip
-    def zip_override(*iterables, strict=False):
-        """Override built-in zip for python<3.10 to ignore `strict` argument."""
-        return _zip(*iterables)
-    builtins.zip = zip_override

qstack/regression/local_kernels.py

@@ -11,10 +11,10 @@
 import ctypes
 import sysconfig
 import warnings
+from itertools import pairwise
 import numpy as np
 import sklearn.metrics.pairwise as _SKLEARN_PAIRWISE
 from qstack.regression import __path__ as REGMODULE_PATH
-from qstack.tools import pairwise
 
 
 RAM_BATCHING_SIZE = 1024**3 * 5  # 5GiB

qstack/tools.py

@@ -4,25 +4,11 @@
 """
 
 import os
-import sys
 import time
 import resource
 import argparse
 import numpy as np
-from itertools import accumulate
-if sys.version_info[1]>=10:
-    from itertools import pairwise
-else:
-    def pairwise(iterable):
-        """Implement itertools.pairwise for python<3.10.
-
-        Taken from https://docs.python.org/3/library/itertools.html#itertools.pairwise
-        """
-        iterator = iter(iterable)
-        a = next(iterator, None)
-        for b in iterator:
-            yield a, b
-            a = b
+from itertools import accumulate, pairwise
 
 
 def unix_time_decorator(func):