Use Try node (#7767)

Bump astroid to 3.0.0a7

doc/whatsnew/fragments/7767.breaking

@@ -0,0 +1,4 @@
+Disables placed in a ``try`` block now apply to the ``except`` block.
+Previously, they only happened to do so in the presence of an ``else`` clause.
+
+Refs #7767

doc/whatsnew/fragments/7767.false_positive

@@ -0,0 +1,5 @@
+Fix false negatives and false positives for ``too-many-try-statements``,
+``too-complex``, and ``too-many-branches`` by correctly counting statements
+under a ``try``.
+
+Refs #7767

pylint/checkers/base/basic_checker.py

@@ -272,13 +272,13 @@ class BasicChecker(_BasicChecker):
 
     def __init__(self, linter: PyLinter) -> None:
         super().__init__(linter)
-        self._tryfinallys: list[nodes.TryFinally] | None = None
+        self._trys: list[nodes.Try]
 
     def open(self) -> None:
         """Initialize visit variables and statistics."""
         py_version = self.linter.config.py_version
         self._py38_plus = py_version >= (3, 8)
-        self._tryfinallys = []
+        self._trys = []
         self.linter.stats.reset_node_count()
 
     @utils.only_required_for_messages(
@@ -478,7 +478,7 @@ def visit_expr(self, node: nodes.Expr) -> None:
         # side effects), else pointless-statement
         if (
             isinstance(expr, (nodes.Yield, nodes.Await))
-            or (isinstance(node.parent, nodes.TryExcept) and node.parent.body == [node])
+            or (isinstance(node.parent, nodes.Try) and node.parent.body == [node])
             or (isinstance(expr, nodes.Const) and expr.value is Ellipsis)
         ):
             return
@@ -768,19 +768,17 @@ def visit_set(self, node: nodes.Set) -> None:
                 )
             values.add(value)
 
-    def visit_tryfinally(self, node: nodes.TryFinally) -> None:
-        """Update try...finally flag."""
-        assert self._tryfinallys is not None
-        self._tryfinallys.append(node)
+    def visit_try(self, node: nodes.Try) -> None:
+        """Update try block flag."""
+        self._trys.append(node)
 
         for final_node in node.finalbody:
             for return_node in final_node.nodes_of_class(nodes.Return):
                 self.add_message("return-in-finally", node=return_node, confidence=HIGH)
 
-    def leave_tryfinally(self, _: nodes.TryFinally) -> None:
-        """Update try...finally flag."""
-        assert self._tryfinallys is not None
-        self._tryfinallys.pop()
+    def leave_try(self, _: nodes.Try) -> None:
+        """Update try block flag."""
+        self._trys.pop()
 
     def _check_unreachable(
         self,
@@ -816,8 +814,8 @@ def _check_not_in_finally(
         If we find a parent which type is in breaker_classes before
         a 'try...finally' block we skip the whole check.
         """
-        # if self._tryfinallys is empty, we're not an in try...finally block
-        if not self._tryfinallys:
+        # if self._trys is empty, we're not an in try block
+        if not self._trys:
             return
         # the node could be a grand-grand...-child of the 'try...finally'
         _parent = node.parent

pylint/checkers/base/basic_error_checker.py

@@ -496,7 +496,7 @@ def _check_in_loop(
             if isinstance(parent, (nodes.ClassDef, nodes.FunctionDef)):
                 break
             if (
-                isinstance(parent, nodes.TryFinally)
+                isinstance(parent, nodes.Try)
                 and node in parent.finalbody
                 and isinstance(node, nodes.Continue)
                 and not self._py38_plus

pylint/checkers/design_analysis.py

@@ -593,19 +593,16 @@ def visit_default(self, node: nodes.NodeNG) -> None:
         if node.is_statement:
             self._inc_all_stmts(1)
 
-    def visit_tryexcept(self, node: nodes.TryExcept) -> None:
+    def visit_try(self, node: nodes.Try) -> None:
         """Increments the branches counter."""
         branches = len(node.handlers)
         if node.orelse:
             branches += 1
+        if node.finalbody:
+            branches += 1
         self._inc_branch(node, branches)
         self._inc_all_stmts(branches)
 
-    def visit_tryfinally(self, node: nodes.TryFinally) -> None:
-        """Increments the branches counter."""
-        self._inc_branch(node, 2)
-        self._inc_all_stmts(2)
-
     @only_required_for_messages("too-many-boolean-expressions", "too-many-branches")
     def visit_if(self, node: nodes.If) -> None:
         """Increments the branches counter and checks boolean expressions."""

pylint/checkers/exceptions.py

@@ -348,7 +348,7 @@ def _check_misplaced_bare_raise(self, node: nodes.Raise) -> None:
 
         current = node
         # Stop when a new scope is generated or when the raise
-        # statement is found inside a TryFinally.
+        # statement is found inside a Try.
         ignores = (nodes.ExceptHandler, nodes.FunctionDef)
         while current and not isinstance(current.parent, ignores):
             current = current.parent
@@ -473,7 +473,7 @@ def _check_catching_non_exception(
                     "catching-non-exception", node=handler.type, args=(exc.name,)
                 )
 
-    def _check_try_except_raise(self, node: nodes.TryExcept) -> None:
+    def _check_try_except_raise(self, node: nodes.Try) -> None:
         def gather_exceptions_from_handler(
             handler: nodes.ExceptHandler,
         ) -> list[InferenceResult] | None:
@@ -556,7 +556,7 @@ def visit_compare(self, node: nodes.Compare) -> None:
         "catching-non-exception",
         "duplicate-except",
     )
-    def visit_tryexcept(self, node: nodes.TryExcept) -> None:
+    def visit_try(self, node: nodes.Try) -> None:
         """Check for empty except."""
         self._check_try_except_raise(node)
         exceptions_classes: list[Any] = []

pylint/checkers/format.py

@@ -496,14 +496,6 @@ def visit_default(self, node: nodes.NodeNG) -> None:
         prev_sibl = node.previous_sibling()
         if prev_sibl is not None:
             prev_line = prev_sibl.fromlineno
-        # The line on which a 'finally': occurs in a 'try/finally'
-        # is not directly represented in the AST. We infer it
-        # by taking the last line of the body and adding 1, which
-        # should be the line of finally:
-        elif (
-            isinstance(node.parent, nodes.TryFinally) and node in node.parent.finalbody
-        ):
-            prev_line = node.parent.body[0].tolineno + 1
         elif isinstance(node.parent, nodes.Module):
             prev_line = 0
         else:
@@ -534,12 +526,6 @@ def _check_multi_statement_line(self, node: nodes.NodeNG, line: int) -> None:
         # in with statements.
         if isinstance(node, nodes.With):
             return
-        # For try... except... finally..., the two nodes
-        # appear to be on the same line due to how the AST is built.
-        if isinstance(node, nodes.TryExcept) and isinstance(
-            node.parent, nodes.TryFinally
-        ):
-            return
         if (
             isinstance(node.parent, nodes.If)
             and not node.parent.orelse

pylint/checkers/imports.py

@@ -617,8 +617,7 @@ def compute_first_non_import_node(
         | nodes.IfExp
         | nodes.Assign
         | nodes.AssignAttr
-        | nodes.TryExcept
-        | nodes.TryFinally,
+        | nodes.Try,
     ) -> None:
         # if the node does not contain an import instruction, and if it is the
         # first node of the module, keep a track of it (all the import positions
@@ -628,11 +627,7 @@ def compute_first_non_import_node(
             return
         if not isinstance(node.parent, nodes.Module):
             return
-        nested_allowed = [nodes.TryExcept, nodes.TryFinally]
-        is_nested_allowed = [
-            allowed for allowed in nested_allowed if isinstance(node, allowed)
-        ]
-        if is_nested_allowed and any(
+        if isinstance(node, nodes.Try) and any(
             node.nodes_of_class((nodes.Import, nodes.ImportFrom))
         ):
             return
@@ -649,9 +644,7 @@ def compute_first_non_import_node(
                 return
         self._first_non_import_node = node
 
-    visit_tryfinally = (
-        visit_tryexcept
-    ) = (
+    visit_try = (
         visit_assignattr
     ) = (
         visit_assign
@@ -675,7 +668,7 @@ def visit_functiondef(
         while not isinstance(root.parent, nodes.Module):
             root = root.parent
 
-        if isinstance(root, (nodes.If, nodes.TryFinally, nodes.TryExcept)):
+        if isinstance(root, (nodes.If, nodes.Try)):
             if any(root.nodes_of_class((nodes.Import, nodes.ImportFrom))):
                 return
 

pylint/checkers/refactoring/refactoring_checker.py

@@ -27,9 +27,7 @@
     from pylint.lint import PyLinter
 
 
-NodesWithNestedBlocks = Union[
-    nodes.TryExcept, nodes.TryFinally, nodes.While, nodes.For, nodes.If
-]
+NodesWithNestedBlocks = Union[nodes.Try, nodes.While, nodes.For, nodes.If]
 
 KNOWN_INFINITE_ITERATORS = {"itertools.count", "itertools.cycle"}
 BUILTIN_EXIT_FUNCS = frozenset(("quit", "exit"))
@@ -71,7 +69,7 @@ def _if_statement_is_always_returning(
 
 
 def _except_statement_is_always_returning(
-    node: nodes.TryExcept, returning_node_class: nodes.NodeNG
+    node: nodes.Try, returning_node_class: nodes.NodeNG
 ) -> bool:
     """Detect if all except statements return."""
     return all(
@@ -653,15 +651,13 @@ def leave_module(self, _: nodes.Module) -> None:
         self._init()
 
     @utils.only_required_for_messages("too-many-nested-blocks", "no-else-return")
-    def visit_tryexcept(self, node: nodes.TryExcept | nodes.TryFinally) -> None:
+    def visit_try(self, node: nodes.Try) -> None:
         self._check_nested_blocks(node)
 
-        if isinstance(node, nodes.TryExcept):
-            self._check_superfluous_else_return(node)
-            self._check_superfluous_else_raise(node)
+        self._check_superfluous_else_return(node)
+        self._check_superfluous_else_raise(node)
 
-    visit_tryfinally = visit_tryexcept
-    visit_while = visit_tryexcept
+    visit_while = visit_try
 
     def _check_redefined_argument_from_local(self, name_node: nodes.AssignName) -> None:
         if self._dummy_rgx and self._dummy_rgx.match(name_node.name):
@@ -723,13 +719,11 @@ def visit_with(self, node: nodes.With) -> None:
 
     def _check_superfluous_else(
         self,
-        node: nodes.If | nodes.TryExcept,
+        node: nodes.If | nodes.Try,
         msg_id: str,
         returning_node_class: nodes.NodeNG,
     ) -> None:
-        if isinstance(node, nodes.TryExcept) and isinstance(
-            node.parent, nodes.TryFinally
-        ):
+        if isinstance(node, nodes.Try) and node.finalbody:
             # Not interested in try/except/else/finally statements.
             return
 
@@ -745,7 +739,8 @@ def _check_superfluous_else(
             isinstance(node, nodes.If)
             and _if_statement_is_always_returning(node, returning_node_class)
         ) or (
-            isinstance(node, nodes.TryExcept)
+            isinstance(node, nodes.Try)
+            and not node.finalbody
             and _except_statement_is_always_returning(node, returning_node_class)
         ):
             orelse = node.orelse[0]
@@ -1962,7 +1957,7 @@ def _is_node_return_ended(self, node: nodes.NodeNG) -> bool:
             return self._is_raise_node_return_ended(node)
         if isinstance(node, nodes.If):
             return self._is_if_node_return_ended(node)
-        if isinstance(node, nodes.TryExcept):
+        if isinstance(node, nodes.Try):
             handlers = {
                 _child
                 for _child in node.get_children()

pylint/checkers/utils.py

@@ -379,8 +379,7 @@ def is_defined_before(var_node: nodes.Name) -> bool:
                     nodes.For,
                     nodes.While,
                     nodes.With,
-                    nodes.TryExcept,
-                    nodes.TryFinally,
+                    nodes.Try,
                     nodes.ExceptHandler,
                 ),
             ):
@@ -988,10 +987,10 @@ def unimplemented_abstract_methods(
 
 def find_try_except_wrapper_node(
     node: nodes.NodeNG,
-) -> nodes.ExceptHandler | nodes.TryExcept | None:
-    """Return the ExceptHandler or the TryExcept node in which the node is."""
+) -> nodes.ExceptHandler | nodes.Try | None:
+    """Return the ExceptHandler or the Try node in which the node is."""
     current = node
-    ignores = (nodes.ExceptHandler, nodes.TryExcept)
+    ignores = (nodes.ExceptHandler, nodes.Try)
     while current and not isinstance(current.parent, ignores):
         current = current.parent
 
@@ -1002,7 +1001,7 @@ def find_try_except_wrapper_node(
 
 def find_except_wrapper_node_in_scope(
     node: nodes.NodeNG,
-) -> nodes.ExceptHandler | nodes.TryExcept | None:
+) -> nodes.ExceptHandler | None:
     """Return the ExceptHandler in which the node is, without going out of scope."""
     for current in node.node_ancestors():
         if isinstance(current, astroid.scoped_nodes.LocalsDictNodeNG):
@@ -1062,7 +1061,7 @@ def get_exception_handlers(
         list: the collection of handlers that are handling the exception or None.
     """
     context = find_try_except_wrapper_node(node)
-    if isinstance(context, nodes.TryExcept):
+    if isinstance(context, nodes.Try):
         return [
             handler for handler in context.handlers if error_of_type(handler, exception)
         ]
@@ -1133,13 +1132,13 @@ def is_node_inside_try_except(node: nodes.Raise) -> bool:
         bool: True if the node is inside a try/except statement, False otherwise.
     """
     context = find_try_except_wrapper_node(node)
-    return isinstance(context, nodes.TryExcept)
+    return isinstance(context, nodes.Try)
 
 
 def node_ignores_exception(
     node: nodes.NodeNG, exception: type[Exception] | str = Exception
 ) -> bool:
-    """Check if the node is in a TryExcept which handles the given exception.
+    """Check if the node is in a Try which handles the given exception.
 
     If the exception is not given, the function is going to look for bare
     excepts.
@@ -1918,7 +1917,7 @@ def get_node_first_ancestor_of_type_and_its_child(
     descendant visited directly before reaching the sought ancestor.
 
     Useful for extracting whether a statement is guarded by a try, except, or finally
-    when searching for a TryFinally ancestor.
+    when searching for a Try ancestor.
     """
     child = node
     for ancestor in node.node_ancestors():