Add default 'except:' must be last.

parso/python/normalizer.py

@@ -58,6 +58,16 @@ class ErrorFinder(Normalizer):
             else:
                 self._add_syntax_error("invalid syntax", leaf)
         elif node.type in _BLOCK_STMTS:
+            if node.type == 'try_stmt':
+                default_except = None
+                for except_clause in node.children[3::3]:
+                    if except_clause in ('else', 'finally'):
+                        break
+                    if except_clause == 'except':
+                        default_except = except_clause
+                    elif default_except is not None:
+                        self._add_syntax_error("default 'except:' must be last", default_except)
+
             with self._context.add_block(node):
                 if len(self._context.blocks) == _MAX_BLOCK_SIZE:
                     self._add_syntax_error("too many statically nested blocks", node)

test/normalizer_issue_files/allowed_syntax.py

@@ -14,3 +14,19 @@ for x in [1]:
 for x in [1]:
     break
     continue
+
+try:
+    pass
+except ZeroDivisionError:
+    pass
+    #: E722:0
+except:
+    pass
+
+try:
+    pass
+    #: E722:0 E901:0
+except:
+    pass
+except ZeroDivisionError:
+    pass

test/test_python_errors.py

@@ -70,6 +70,7 @@ def test_indentation_errors(code, positions):
         'continue',
         'break',
         'return',
+        'try: pass\nexcept: pass\nexcept X: pass',
 
         # IndentationError
         ' foo',