safer safe_version (#353)

* Update test_importing.py

* Update changelog.rst

* Update importing.py

Author: loriab

docs/changelog.rst

@@ -41,6 +41,8 @@ Bug Fixes
 Misc.
 +++++
 - (:pr:`342`) Update some docs settings and requirements for newer tools.
+- (:pr:`353`) copied in pkg_resources.safe_version code as follow-up to Eric switch to packaging as both nwchem and gamess were now working. 
+the try_harder_safe_version might be even bettter
 
 
 0.28.0 / 2024-06-21

qcelemental/tests/test_importing.py

@@ -154,6 +154,14 @@ def test_parse_version():
     assert str(v) == "5.3.1"
 
 
-def test_safe_version():
-    v = qcel.util.safe_version("5.3.1")
-    assert v == "5.3.1"
+@pytest.mark.parametrize(
+    "inp,out",
+    [
+        ("5.3.1", "5.3.1"),
+        ("30 SEP 2023 (R2)", "30.SEP.2023.-R2-"),
+        ("7.0.0+N/A", "7.0.0-N-A"),
+    ],
+)
+def test_safe_version(inp, out):
+    v = qcel.util.safe_version(inp)
+    assert v == out

qcelemental/util/importing.py

@@ -1,4 +1,5 @@
 import os
+import re
 import shutil
 import sys
 from typing import TYPE_CHECKING, List, Union
@@ -132,14 +133,23 @@ def which(
 
 def safe_version(version) -> str:
     """
-    Package resources is a very slow load
+    Convert an arbitrary string to a standard version string by pkg_resources definition.
     """
-    return str(parse_version(version))
+    # from https://github.com/pypa/setuptools/blob/main/pkg_resources/__init__.py
+    # original function deprecated and never one-to-one replaced
+    from packaging.version import InvalidVersion, Version
+
+    try:
+        # normalize the version
+        return str(Version(version))
+    except InvalidVersion:
+        version = version.replace(" ", ".")
+        return re.sub("[^A-Za-z0-9.]+", "-", version)
 
 
 def parse_version(version) -> "Version":
     """
-    Package resources is a very slow load
+    Legitimate version
     """
     from packaging.version import parse