Have mccabe consider all statements as statements

mccabe.py

@@ -160,10 +160,11 @@ class PathGraphingAstVisitor(ASTVisitor):
         name = "Stmt %d" % lineno
         self.appendPathNode(name)
-    visitAssert = visitAssign = visitAugAssign = visitDelete = visitPrint = \
-        visitRaise = visitYield = visitImport = visitCall = visitSubscript = \
-        visitPass = visitContinue = visitBreak = visitGlobal = visitReturn = \
-        visitAwait = visitSimpleStatement
+    def default(self, node):
+        if isinstance(node, ast.stmt):
+            self.visitSimpleStatement(node)
+        else:
+            super(PathGraphingAstVisitor, self).default(node)
     def visitLoop(self, node):
         name = "Loop %d" % node.lineno

test_mccabe.py

@@ -16,6 +16,12 @@ from mccabe import get_code_complexity
 trivial = 'def f(): pass'
+expr_as_statement = '''\
+def f():
+    """docstring"""
+'''
+
+
 sequential = """\
 def f(n):
     k = n + 4
@@ -176,6 +182,10 @@ class McCabeTestCase(unittest.TestCase):
         printed_message = self.strio.getvalue()
         self.assertEqual(printed_message, "")
+    def test_expr_as_statement(self):
+        complexity = get_complexity_number(expr_as_statement, self.strio)
+        self.assertEqual(complexity, 1)
+
     def test_try_else(self):
         self.assert_complexity(try_else, 4)