breaking: drop Python 3.7 support (#3185)

... per discussion.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

backend/find_tensorflow.py

@@ -28,7 +28,7 @@
 )
 
 
-@lru_cache()
+@lru_cache
 def find_tensorflow() -> Tuple[Optional[str], List[str]]:
     """Find TensorFlow library.
 
@@ -111,7 +111,7 @@ def find_tensorflow() -> Tuple[Optional[str], List[str]]:
     return tf_install_dir, requires
 
 
-@lru_cache()
+@lru_cache
 def get_tf_requirement(tf_version: str = "") -> dict:
     """Get TensorFlow requirement (CPU) when TF is not installed.
 
@@ -189,7 +189,7 @@ def get_tf_requirement(tf_version: str = "") -> dict:
         }
 
 
-@lru_cache()
+@lru_cache
 def get_tf_version(tf_path: Union[str, Path]) -> str:
     """Get TF version from a TF Python library path.
 

backend/read_env.py

@@ -19,7 +19,7 @@
 )
 
 
-@lru_cache()
+@lru_cache
 def get_argument_from_env() -> Tuple[str, list, list, dict, str]:
     """Get the arguments from environment variables.
 

deepmd/tf/utils/tabulate.py

@@ -770,12 +770,12 @@ def _get_layer_size(self):
         return layer_size
 
     @property
-    @lru_cache()
+    @lru_cache
     def _n_all_excluded(self) -> int:
         """Then number of types excluding all types."""
         return sum(int(self._all_excluded(ii)) for ii in range(0, self.ntypes))
 
-    @lru_cache()
+    @lru_cache
     def _all_excluded(self, ii: int) -> bool:
         """Check if type ii excluds all types.
 

doc/development/coding-conventions.rst

@@ -30,7 +30,7 @@ Rules
 -----
 
 The code must be compatible with the oldest supported version of python
-which is 3.7
+which is 3.8.
 
 The project follows the generic coding conventions as
 specified in the `Style Guide for Python Code`_, `Docstring

doc/install/easy-install.md

@@ -8,6 +8,10 @@ After your easy installation, DeePMD-kit (`dp`) and LAMMPS (`lmp`) will be avail
 Note: The off-line packages and conda packages require the [GNU C Library](https://www.gnu.org/software/libc/) 2.17 or above. The GPU version requires [compatible NVIDIA driver](https://docs.nvidia.com/deploy/cuda-compatibility/index.html#minor-version-compatibility) to be installed in advance. It is possible to force conda to [override detection](https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-virtual.html#overriding-detected-packages) when installation, but these requirements are still necessary during runtime.
 :::
 
+:::{note}
+Python 3.8 or above is required for Python interface.
+:::
+
 - [Install off-line packages](#install-off-line-packages)
 - [Install with conda](#install-with-conda)
 - [Install with docker](#install-with-docker)

doc/install/install-from-source.md

@@ -16,12 +16,13 @@ deepmd_source_dir=`pwd`
 
 ## Install the python interface
 ### Install Tensorflow's python interface
-First, check the python version on your machine
+First, check the python version on your machine.
+Python 3.8 or above is required.
 ```bash
 python --version
 ```
 
-We follow the virtual environment approach to install TensorFlow's Python interface. The full instruction can be found on the official [TensorFlow website](https://www.tensorflow.org/install/pip). TensorFlow 1.8 or later is supported. Now we assume that the Python interface will be installed to the virtual environment directory `$tensorflow_venv`
+We follow the virtual environment approach to install TensorFlow's Python interface. The full instruction can be found on the official [TensorFlow website](https://www.tensorflow.org/install/pip). TensorFlow 2.2 or later is supported. Now we assume that the Python interface will be installed to the virtual environment directory `$tensorflow_venv`
 ```bash
 virtualenv -p python3 $tensorflow_venv
 source $tensorflow_venv/bin/activate

pyproject.toml

@@ -27,7 +27,7 @@ classifiers = [
     "Programming Language :: Python :: 3 :: Only",
     "Environment :: GPU :: NVIDIA CUDA :: 12 :: 12.2",
     "Intended Audience :: Science/Research",
-    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
     "License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)",
     "Topic :: Scientific/Engineering :: Artificial Intelligence",
     "Topic :: Scientific/Engineering :: Physics",
@@ -46,7 +46,7 @@ dependencies = [
     'wcmatch',
     'packaging',
 ]
-requires-python = ">=3.7"
+requires-python = ">=3.8"
 keywords = ["deepmd"]
 
 [project.entry-points."lammps.plugins"]

source/install/build_tf.py

@@ -423,14 +423,14 @@ def __init__(self, version="1.11.0") -> None:
         self.version = version
 
     @property
-    @lru_cache()
+    @lru_cache
     def resources(self) -> Dict[str, OnlineResource]:
         return {
             "bazelisk": RESOURCES["bazelisk-" + self.version],
         }
 
     @property
-    @lru_cache()
+    @lru_cache
     def dependencies(self) -> Dict[str, Build]:
         return {}
 
@@ -449,12 +449,12 @@ class BuildNumpy(Build):
     """Build NumPy."""
 
     @property
-    @lru_cache()
+    @lru_cache
     def resources(self) -> Dict[str, OnlineResource]:
         return {}
 
     @property
-    @lru_cache()
+    @lru_cache
     def dependencies(self) -> Dict[str, Build]:
         return {}
 
@@ -481,12 +481,12 @@ class BuildCUDA(Build):
     """Find CUDA."""
 
     @property
-    @lru_cache()
+    @lru_cache
     def resources(self) -> Dict[str, OnlineResource]:
         return {}
 
     @property
-    @lru_cache()
+    @lru_cache
     def dependencies(self) -> Dict[str, Build]:
         return {}
 
@@ -536,7 +536,7 @@ def cudnn_version(self):
         )
 
     @property
-    @lru_cache()
+    @lru_cache
     def cuda_compute_capabilities(self):
         """Get cuda compute capabilities."""
         cuda_version = tuple(map(int, self.cuda_version.split(".")))
@@ -554,12 +554,12 @@ class BuildROCM(Build):
     """Find ROCm."""
 
     @property
-    @lru_cache()
+    @lru_cache
     def resources(self) -> Dict[str, OnlineResource]:
         return {}
 
     @property
-    @lru_cache()
+    @lru_cache
     def dependencies(self) -> Dict[str, Build]:
         return {}
 
@@ -599,14 +599,14 @@ def __init__(
         self.enable_rocm = enable_rocm
 
     @property
-    @lru_cache()
+    @lru_cache
     def resources(self) -> Dict[str, OnlineResource]:
         return {
             "tensorflow": RESOURCES["tensorflow-" + self.version],
         }
 
     @property
-    @lru_cache()
+    @lru_cache
     def dependencies(self) -> Dict[str, Build]:
         optional_dep = {}
         if self.enable_cuda: