Start Python3 execption handling

test/simple_source/README

@@ -4,4 +4,9 @@ across all versions of Python.
 Their simnplicity is to try to make it easier to debug grammar
 and AST walking routines.
 
-This code originally taken from https://github.com/DarkFenX/uncompyle3
+The numbers in the filenames are to assist running the programs from
+the simplest to more complex. For example, many tests have assignment
+statements or function calls, so we want to test those constructs
+first.
+
+Code and organization merged from uncompyle3, uncompyle{,2}, and pycdc

test/simple_source/exception/01_try_except.py

@@ -1,4 +1,27 @@
+# Tests:
+#   trystmt ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK
+#               try_middle COME_FROM
+#   except_stmt ::= except
+
 try:
     x = 1
 except:
     pass
+
+# Tests:
+#   trystmt ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK
+#               try_middle COME_FROM
+#   except_stmt ::= except_cond1 except_suite
+#   except_suite ::= ...
+
+try:
+    x = 1
+except ImportError:
+    pass
+
+try:
+    x = 2
+except ImportError:
+    x = 3
+finally:
+    x = 4

test/simple_source/misc/assign_none_str.py

@@ -1 +0,0 @@
-vario = 'None'

test/simple_source/simple_stmts/00_assign.py

@@ -1,4 +1,6 @@
 # Tests:
 # assign ::= expr designator
 
-vario = 556
+a = 'None'
+b = None
+c = 556