Codebase modernisation (#464)

* Run pyupgrade --py36-plus on all files

This should update the codebase to use modern Python 3 features.

* Drop all `__ne__` methods

This is no longer necessary, since Python 2 support has been dropped.

Co-authored-by: Pradyun Gedam <pradyunsg@users.noreply.github.com>
Co-authored-by: Brett Cannon <brett@python.org>

packaging/_musllinux.py

@@ -98,7 +98,7 @@ def _get_musl_version(executable: str) -> Optional[_MuslVersion]:
     with contextlib.ExitStack() as stack:
         try:
             f = stack.enter_context(open(executable, "rb"))
-        except IOError:
+        except OSError:
             return None
         ld = _parse_ld_musl_from_elf(f)
     if not ld:

packaging/_structures.py

@@ -19,9 +19,6 @@ def __le__(self, other: object) -> bool:
     def __eq__(self, other: object) -> bool:
         return isinstance(other, self.__class__)
 
-    def __ne__(self, other: object) -> bool:
-        return not isinstance(other, self.__class__)
-
     def __gt__(self, other: object) -> bool:
         return True
 
@@ -51,9 +48,6 @@ def __le__(self, other: object) -> bool:
     def __eq__(self, other: object) -> bool:
         return isinstance(other, self.__class__)
 
-    def __ne__(self, other: object) -> bool:
-        return not isinstance(other, self.__class__)
-
     def __gt__(self, other: object) -> bool:
         return False
 

packaging/specifiers.py

@@ -57,13 +57,6 @@ def __eq__(self, other: object) -> bool:
         objects are equal.
         """
 
-    @abc.abstractmethod
-    def __ne__(self, other: object) -> bool:
-        """
-        Returns a boolean representing whether or not the two Specifier like
-        objects are not equal.
-        """
-
     @abc.abstractproperty
     def prereleases(self) -> Optional[bool]:
         """
@@ -119,7 +112,7 @@ def __repr__(self) -> str:
             else ""
         )
 
-        return "<{}({!r}{})>".format(self.__class__.__name__, str(self), pre)
+        return f"<{self.__class__.__name__}({str(self)!r}{pre})>"
 
     def __str__(self) -> str:
         return "{}{}".format(*self._spec)
@@ -142,17 +135,6 @@ def __eq__(self, other: object) -> bool:
 
         return self._canonical_spec == other._canonical_spec
 
-    def __ne__(self, other: object) -> bool:
-        if isinstance(other, str):
-            try:
-                other = self.__class__(str(other))
-            except InvalidSpecifier:
-                return NotImplemented
-        elif not isinstance(other, self.__class__):
-            return NotImplemented
-
-        return self._spec != other._spec
-
     def _get_operator(self, op: str) -> CallableOperator:
         operator_callable: CallableOperator = getattr(
             self, f"_compare_{self._operators[op]}"
@@ -667,7 +649,7 @@ def __repr__(self) -> str:
             else ""
         )
 
-        return "<SpecifierSet({!r}{})>".format(str(self), pre)
+        return f"<SpecifierSet({str(self)!r}{pre})>"
 
     def __str__(self) -> str:
         return ",".join(sorted(str(s) for s in self._specs))
@@ -706,14 +688,6 @@ def __eq__(self, other: object) -> bool:
 
         return self._specs == other._specs
 
-    def __ne__(self, other: object) -> bool:
-        if isinstance(other, (str, _IndividualSpecifier)):
-            other = SpecifierSet(str(other))
-        elif not isinstance(other, SpecifierSet):
-            return NotImplemented
-
-        return self._specs != other._specs
-
     def __len__(self) -> int:
         return len(self._specs)
 

packaging/tags.py

@@ -90,7 +90,7 @@ def __str__(self) -> str:
         return f"{self._interpreter}-{self._abi}-{self._platform}"
 
     def __repr__(self) -> str:
-        return "<{self} @ {self_id}>".format(self=self, self_id=id(self))
+        return f"<{self} @ {id(self)}>"
 
 
 def parse_tag(tag: str) -> FrozenSet[Tag]:
@@ -192,7 +192,7 @@ def cpython_tags(
     if not python_version:
         python_version = sys.version_info[:2]
 
-    interpreter = "cp{}".format(_version_nodot(python_version[:2]))
+    interpreter = f"cp{_version_nodot(python_version[:2])}"
 
     if abis is None:
         if len(python_version) > 1:
@@ -268,11 +268,11 @@ def _py_interpreter_range(py_version: PythonVersion) -> Iterator[str]:
     all previous versions of that major version.
     """
     if len(py_version) > 1:
-        yield "py{version}".format(version=_version_nodot(py_version[:2]))
-    yield "py{major}".format(major=py_version[0])
+        yield f"py{_version_nodot(py_version[:2])}"
+    yield f"py{py_version[0]}"
     if len(py_version) > 1:
         for minor in range(py_version[1] - 1, -1, -1):
-            yield "py{version}".format(version=_version_nodot((py_version[0], minor)))
+            yield f"py{_version_nodot((py_version[0], minor))}"
 
 
 def compatible_tags(