breaking: drop python 3.7 (#783)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

## Release Notes

- **Python Version Support**
  - Dropped support for Python 3.7
  - Now requires Python 3.8 or higher

- **Documentation**
- Updated installation instructions to reflect new Python version
requirements

- **Code Maintenance**
  - Simplified type imports and version-specific code handling
  - Removed legacy version compatibility checks

- **Build Configuration**
  - Updated GitHub Actions workflow to test only Python 3.8 and 3.12

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Han Wang <wang_han@iapcm.ac.cn>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

.github/workflows/test.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.12"]
+        python-version: ["3.8", "3.12"]
 
     steps:
     - uses: actions/checkout@v4

docs/installation.md

@@ -1,6 +1,6 @@
 # Installation
 
-DP-GEN only supports Python 3.7 and above. You can [setup a conda/pip environment](https://docs.deepmodeling.com/faq/conda.html), and then use one of the following methods to install DP-GEN:
+dpdata only supports Python 3.8 and above. You can [setup a conda/pip environment](https://docs.deepmodeling.com/faq/conda.html), and then use one of the following methods to install dpdata:
 
 - Install via pip: `pip install dpdata`
 - Install via conda: `conda install -c conda-forge dpdata`

docs/make_format.py

@@ -2,14 +2,9 @@
 
 import csv
 import os
-import sys
 from collections import defaultdict
 from inspect import Parameter, Signature, cleandoc, signature
-
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
+from typing import Literal
 
 from numpydoc.docscrape import Parameter as numpydoc_Parameter
 from numpydoc.docscrape_sphinx import SphinxDocString

dpdata/stat.py

@@ -116,15 +116,15 @@ class Errors(ErrorsBase):
     SYSTEM_TYPE = LabeledSystem
 
     @property
-    @lru_cache()
+    @lru_cache
     def e_errors(self) -> np.ndarray:
         """Energy errors."""
         assert isinstance(self.system_1, self.SYSTEM_TYPE)
         assert isinstance(self.system_2, self.SYSTEM_TYPE)
         return self.system_1["energies"] - self.system_2["energies"]
 
     @property
-    @lru_cache()
+    @lru_cache
     def f_errors(self) -> np.ndarray:
         """Force errors."""
         assert isinstance(self.system_1, self.SYSTEM_TYPE)
@@ -153,7 +153,7 @@ class MultiErrors(ErrorsBase):
     SYSTEM_TYPE = MultiSystems
 
     @property
-    @lru_cache()
+    @lru_cache
     def e_errors(self) -> np.ndarray:
         """Energy errors."""
         assert isinstance(self.system_1, self.SYSTEM_TYPE)
@@ -166,7 +166,7 @@ def e_errors(self) -> np.ndarray:
         return np.concatenate(errors)
 
     @property
-    @lru_cache()
+    @lru_cache
     def f_errors(self) -> np.ndarray:
         """Force errors."""
         assert isinstance(self.system_1, self.SYSTEM_TYPE)

dpdata/system.py

@@ -5,21 +5,16 @@
 import hashlib
 import numbers
 import os
-import sys
 import warnings
 from copy import deepcopy
 from typing import (
     TYPE_CHECKING,
     Any,
     Iterable,
+    Literal,
     overload,
 )
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
-
 import numpy as np
 
 import dpdata

dpdata/utils.py

@@ -2,14 +2,9 @@
 
 import io
 import os
-import sys
 from contextlib import contextmanager
-from typing import TYPE_CHECKING, Generator, overload
+from typing import TYPE_CHECKING, Generator, Literal, overload
 
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
 import numpy as np
 
 from dpdata.periodic_table import Element

pyproject.toml

@@ -12,7 +12,6 @@ authors = [
 ]
 license = {file = "LICENSE"}
 classifiers = [
-    "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
@@ -28,7 +27,7 @@ dependencies = [
     'importlib_metadata>=1.4; python_version < "3.8"',
     'typing_extensions; python_version < "3.8"',
 ]
-requires-python = ">=3.7"
+requires-python = ">=3.8"
 readme = "README.md"
 keywords = ["lammps", "vasp", "deepmd-kit"]
 

tests/plugin/pyproject.toml

@@ -11,7 +11,7 @@ dependencies = [
     'dpdata',
 ]
 readme = "README.md"
-requires-python = ">=3.7"
+requires-python = ">=3.8"
 
 [project.entry-points.'dpdata.plugins']
 random = "dpdata_plugin_test:ep"