Add dependency on packaging for version parsing (#341)

* test version parsing

* switch from pkg_resources to packaging.version

pyproject.toml

@@ -31,6 +31,10 @@ numpy = [
     { version = ">=1.26.1,<2.0", python = ">=3.9,<3.10" },
     { version = ">=1.26.1", python = ">=3.9,<3.13" },
 ]
+packaging = [
+    { version = ">=24.0", python = ">=3.7,<3.8" },
+    { version = ">=24.1", python = ">=3.8" },
+]
 # qcel is compatible with most any numpy, v1 or v2, but numpy v2 only works with pint >=0.24, which is only available for py >=3.10
 python = "^3.7"
 pint = [

qcelemental/tests/test_importing.py

@@ -147,3 +147,13 @@ def test_which_f_raisemsg():
         qcel.util.which("evills", raise_error=True, raise_msg="Install `evills`.")
 
     assert str(e.value).endswith("Command 'evills' not found in envvar PATH. Install `evills`.")
+
+
+def test_parse_version():
+    v = qcel.util.parse_version("5.3.1")
+    assert str(v) == "5.3.1"
+
+
+def test_safe_version():
+    v = qcel.util.safe_version("5.3.1")
+    assert v == "5.3.1"

qcelemental/util/importing.py

@@ -1,7 +1,10 @@
 import os
 import shutil
 import sys
-from typing import List, Union
+from typing import TYPE_CHECKING, List, Union
+
+if TYPE_CHECKING:
+    from packaging.version import Version
 
 
 def which_import(
@@ -127,20 +130,17 @@ def which(
         return ans
 
 
-def safe_version(*args, **kwargs) -> str:
+def safe_version(version) -> str:
     """
     Package resources is a very slow load
     """
-    import pkg_resources
-
-    version = pkg_resources.safe_version(*args, **kwargs)
-    return version
+    return str(parse_version(version))
 
 
-def parse_version(*args, **kwargs):
+def parse_version(version) -> "Version":
     """
     Package resources is a very slow load
     """
-    import pkg_resources
+    from packaging.version import parse
 
-    return pkg_resources.parse_version(*args, **kwargs)
+    return parse(version)