pylock: simplify

Author: sbidoul

src/packaging/pylock.py

@@ -4,7 +4,7 @@
 import logging
 import re
 import sys
-from collections.abc import Iterable, Mapping, Sequence
+from collections.abc import Mapping, Sequence
 from dataclasses import dataclass
 from datetime import datetime
 from pathlib import Path
@@ -218,16 +218,6 @@ def _get_required_list_of_objects(
     return result
 
 
-def _exactly_one(iterable: Iterable[object]) -> bool:
-    found = False
-    for item in iterable:
-        if item:
-            if found:
-                return False
-            found = True
-    return found
-
-
 def _validate_path_url(path: str | None, url: str | None) -> None:
     if not path and not url:
         raise PylockValidationError("path or url must be provided")
@@ -522,14 +512,14 @@ def __init__(
         if not is_normalized_name(self.name):
             raise PylockValidationError(f"Package name {self.name!r} is not normalized")
         if self.sdist or self.wheels:
-            if any([self.vcs, self.directory, self.archive]):
+            if self.vcs or self.directory or self.archive:
                 raise PylockValidationError(
                     "None of vcs, directory, archive "
                     "must be set if sdist or wheels are set"
                 )
         else:
             # no sdist nor wheels
-            if not _exactly_one([self.vcs, self.directory, self.archive]):
+            if not (bool(self.vcs) ^ bool(self.directory) ^ bool(self.archive)):
                 raise PylockValidationError(
                     "Exactly one of vcs, directory, archive must be set "
                     "if sdist and wheels are not set"

tests/test_pylock.py

@@ -18,7 +18,6 @@
     PylockRequiredKeyError,
     PylockUnsupportedVersionError,
     PylockValidationError,
-    _exactly_one,
     from_dict,
     is_valid_pylock_path,
 )
@@ -44,15 +43,6 @@ def test_pylock_file_name(file_name: str, valid: bool) -> None:
     assert is_valid_pylock_path(Path(file_name)) is valid
 
 
-def test_exactly_one() -> None:
-    assert not _exactly_one([])
-    assert not _exactly_one([False])
-    assert not _exactly_one([False, False])
-    assert not _exactly_one([True, True])
-    assert _exactly_one([True])
-    assert _exactly_one([True, False])
-
-
 # This is the PEP 751 example, with the following differences:
 # - a minor modification to the 'environments' field to use double quotes
 #   instead of single quotes, since that is what 'packaging' does when