diff --git a/Lib/test/exception_hierarchy.txt b/Lib/test/exception_hierarchy.txt
new file mode 100644
index 000000000..15f4491cf
--- /dev/null
+++ b/Lib/test/exception_hierarchy.txt
@@ -0,0 +1,65 @@
+BaseException
+ +-- SystemExit
+ +-- KeyboardInterrupt
+ +-- GeneratorExit
+ +-- Exception
+      +-- StopIteration
+      +-- StopAsyncIteration
+      +-- ArithmeticError
+      |    +-- FloatingPointError
+      |    +-- OverflowError
+      |    +-- ZeroDivisionError
+      +-- AssertionError
+      +-- AttributeError
+      +-- BufferError
+      +-- EOFError
+      +-- ImportError
+      |    +-- ModuleNotFoundError
+      +-- LookupError
+      |    +-- IndexError
+      |    +-- KeyError
+      +-- MemoryError
+      +-- NameError
+      |    +-- UnboundLocalError
+      +-- OSError
+      |    +-- BlockingIOError
+      |    +-- ChildProcessError
+      |    +-- ConnectionError
+      |    |    +-- BrokenPipeError
+      |    |    +-- ConnectionAbortedError
+      |    |    +-- ConnectionRefusedError
+      |    |    +-- ConnectionResetError
+      |    +-- FileExistsError
+      |    +-- FileNotFoundError
+      |    +-- InterruptedError
+      |    +-- IsADirectoryError
+      |    +-- NotADirectoryError
+      |    +-- PermissionError
+      |    +-- ProcessLookupError
+      |    +-- TimeoutError
+      +-- ReferenceError
+      +-- RuntimeError
+      |    +-- NotImplementedError
+      |    +-- RecursionError
+      +-- SyntaxError
+      |    +-- TargetScopeError
+      |    +-- IndentationError
+      |         +-- TabError
+      +-- SystemError
+      +-- TypeError
+      +-- ValueError
+      |    +-- UnicodeError
+      |         +-- UnicodeDecodeError
+      |         +-- UnicodeEncodeError
+      |         +-- UnicodeTranslateError
+      +-- Warning
+           +-- DeprecationWarning
+           +-- PendingDeprecationWarning
+           +-- RuntimeWarning
+           +-- SyntaxWarning
+           +-- UserWarning
+           +-- FutureWarning
+           +-- ImportWarning
+           +-- UnicodeWarning
+           +-- BytesWarning
+           +-- ResourceWarning
diff --git a/Lib/test/test_baseexception.py b/Lib/test/test_baseexception.py
new file mode 100644
index 000000000..06e9ab3bd
--- /dev/null
+++ b/Lib/test/test_baseexception.py
@@ -0,0 +1,189 @@
+import unittest
+import builtins
+import os
+from platform import system as platform_system
+
+
+class ExceptionClassTests(unittest.TestCase):
+
+    """Tests for anything relating to exception objects themselves (e.g.,
+    inheritance hierarchy)"""
+
+    def test_builtins_new_style(self):
+        self.assertTrue(issubclass(Exception, object))
+
+    def verify_instance_interface(self, ins):
+        for attr in ("args", "__str__", "__repr__"):
+            self.assertTrue(hasattr(ins, attr),
+                    "%s missing %s attribute" %
+                        (ins.__class__.__name__, attr))
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_inheritance(self):
+        # Make sure the inheritance hierarchy matches the documentation
+        exc_set = set()
+        for object_ in builtins.__dict__.values():
+            try:
+                if issubclass(object_, BaseException):
+                    exc_set.add(object_.__name__)
+            except TypeError:
+                pass
+
+        inheritance_tree = open(os.path.join(os.path.split(__file__)[0],
+                                                'exception_hierarchy.txt'))
+        try:
+            superclass_name = inheritance_tree.readline().rstrip()
+            try:
+                last_exc = getattr(builtins, superclass_name)
+            except AttributeError:
+                self.fail("base class %s not a built-in" % superclass_name)
+            self.assertIn(superclass_name, exc_set,
+                          '%s not found' % superclass_name)
+            exc_set.discard(superclass_name)
+            superclasses = []  # Loop will insert base exception
+            last_depth = 0
+            for exc_line in inheritance_tree:
+                exc_line = exc_line.rstrip()
+                depth = exc_line.rindex('-')
+                exc_name = exc_line[depth+2:]  # Slice past space
+                if '(' in exc_name:
+                    paren_index = exc_name.index('(')
+                    platform_name = exc_name[paren_index+1:-1]
+                    exc_name = exc_name[:paren_index-1]  # Slice off space
+                    if platform_system() != platform_name:
+                        exc_set.discard(exc_name)
+                        continue
+                if '[' in exc_name:
+                    left_bracket = exc_name.index('[')
+                    exc_name = exc_name[:left_bracket-1]  # cover space
+                try:
+                    exc = getattr(builtins, exc_name)
+                except AttributeError:
+                    self.fail("%s not a built-in exception" % exc_name)
+                if last_depth < depth:
+                    superclasses.append((last_depth, last_exc))
+                elif last_depth > depth:
+                    while superclasses[-1][0] >= depth:
+                        superclasses.pop()
+                self.assertTrue(issubclass(exc, superclasses[-1][1]),
+                "%s is not a subclass of %s" % (exc.__name__,
+                    superclasses[-1][1].__name__))
+                try:  # Some exceptions require arguments; just skip them
+                    self.verify_instance_interface(exc())
+                except TypeError:
+                    pass
+                self.assertIn(exc_name, exc_set)
+                exc_set.discard(exc_name)
+                last_exc = exc
+                last_depth = depth
+        finally:
+            inheritance_tree.close()
+        self.assertEqual(len(exc_set), 0, "%s not accounted for" % exc_set)
+
+    interface_tests = ("length", "args", "str", "repr")
+
+    def interface_test_driver(self, results):
+        for test_name, (given, expected) in zip(self.interface_tests, results):
+            self.assertEqual(given, expected, "%s: %s != %s" % (test_name,
+                given, expected))
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_interface_single_arg(self):
+        # Make sure interface works properly when given a single argument
+        arg = "spam"
+        exc = Exception(arg)
+        results = ([len(exc.args), 1], [exc.args[0], arg],
+                   [str(exc), str(arg)],
+            [repr(exc), '%s(%r)' % (exc.__class__.__name__, arg)])
+        self.interface_test_driver(results)
+
+    def test_interface_multi_arg(self):
+        # Make sure interface correct when multiple arguments given
+        arg_count = 3
+        args = tuple(range(arg_count))
+        exc = Exception(*args)
+        results = ([len(exc.args), arg_count], [exc.args, args],
+                [str(exc), str(args)],
+                [repr(exc), exc.__class__.__name__ + repr(exc.args)])
+        self.interface_test_driver(results)
+
+    def test_interface_no_arg(self):
+        # Make sure that with no args that interface is correct
+        exc = Exception()
+        results = ([len(exc.args), 0], [exc.args, tuple()],
+                [str(exc), ''],
+                [repr(exc), exc.__class__.__name__ + '()'])
+        self.interface_test_driver(results)
+
+class UsageTests(unittest.TestCase):
+
+    """Test usage of exceptions"""
+
+    def raise_fails(self, object_):
+        """Make sure that raising 'object_' triggers a TypeError."""
+        try:
+            raise object_
+        except TypeError:
+            return  # What is expected.
+        self.fail("TypeError expected for raising %s" % type(object_))
+
+    def catch_fails(self, object_):
+        """Catching 'object_' should raise a TypeError."""
+        try:
+            try:
+                raise Exception
+            except object_:
+                pass
+        except TypeError:
+            pass
+        except Exception:
+            self.fail("TypeError expected when catching %s" % type(object_))
+
+        try:
+            try:
+                raise Exception
+            except (object_,):
+                pass
+        except TypeError:
+            return
+        except Exception:
+            self.fail("TypeError expected when catching %s as specified in a "
+                        "tuple" % type(object_))
+
+    def test_raise_new_style_non_exception(self):
+        # You cannot raise a new-style class that does not inherit from
+        # BaseException; the ability was not possible until BaseException's
+        # introduction so no need to support new-style objects that do not
+        # inherit from it.
+        class NewStyleClass(object):
+            pass
+        self.raise_fails(NewStyleClass)
+        self.raise_fails(NewStyleClass())
+
+    def test_raise_string(self):
+        # Raising a string raises TypeError.
+        self.raise_fails("spam")
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_catch_non_BaseException(self):
+        # Trying to catch an object that does not inherit from BaseException
+        # is not allowed.
+        class NonBaseException(object):
+            pass
+        self.catch_fails(NonBaseException)
+        self.catch_fails(NonBaseException())
+
+    def test_catch_BaseException_instance(self):
+        # Catching an instance of a BaseException subclass won't work.
+        self.catch_fails(BaseException())
+
+    def test_catch_string(self):
+        # Catching a string is bad.
+        self.catch_fails("spam")
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/test/test_int.py b/Lib/test/test_int.py
new file mode 100644
index 000000000..29dfe9920
--- /dev/null
+++ b/Lib/test/test_int.py
@@ -0,0 +1,530 @@
+import sys
+
+import unittest
+from test import support
+# from test.test_grammar import (VALID_UNDERSCORE_LITERALS,
+#                                INVALID_UNDERSCORE_LITERALS)
+
+L = [
+        ('0', 0),
+        ('1', 1),
+        ('9', 9),
+        ('10', 10),
+        ('99', 99),
+        ('100', 100),
+        ('314', 314),
+        (' 314', 314),
+        ('314 ', 314),
+        ('  \t\t  314  \t\t  ', 314),
+        (repr(sys.maxsize), sys.maxsize),
+        ('  1x', ValueError),
+        ('  1  ', 1),
+        ('  1\02  ', ValueError),
+        ('', ValueError),
+        (' ', ValueError),
+        ('  \t\t  ', ValueError),
+        ("\u0200", ValueError)
+]
+
+class IntSubclass(int):
+    pass
+
+class IntTestCases(unittest.TestCase):
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_basic(self):
+        self.assertEqual(int(314), 314)
+        self.assertEqual(int(3.14), 3)
+        # Check that conversion from float truncates towards zero
+        self.assertEqual(int(-3.14), -3)
+        self.assertEqual(int(3.9), 3)
+        self.assertEqual(int(-3.9), -3)
+        self.assertEqual(int(3.5), 3)
+        self.assertEqual(int(-3.5), -3)
+        self.assertEqual(int("-3"), -3)
+        self.assertEqual(int(" -3 "), -3)
+        self.assertEqual(int("\N{EM SPACE}-3\N{EN SPACE}"), -3)
+        # Different base:
+        self.assertEqual(int("10",16), 16)
+        # Test conversion from strings and various anomalies
+        for s, v in L:
+            for sign in "", "+", "-":
+                for prefix in "", " ", "\t", "  \t\t  ":
+                    ss = prefix + sign + s
+                    vv = v
+                    if sign == "-" and v is not ValueError:
+                        vv = -v
+                    try:
+                        self.assertEqual(int(ss), vv)
+                    except ValueError:
+                        pass
+
+        s = repr(-1-sys.maxsize)
+        x = int(s)
+        self.assertEqual(x+1, -sys.maxsize)
+        self.assertIsInstance(x, int)
+        # should return int
+        self.assertEqual(int(s[1:]), sys.maxsize+1)
+
+        # should return int
+        x = int(1e100)
+        self.assertIsInstance(x, int)
+        x = int(-1e100)
+        self.assertIsInstance(x, int)
+
+
+        # SF bug 434186:  0x80000000/2 != 0x80000000>>1.
+        # Worked by accident in Windows release build, but failed in debug build.
+        # Failed in all Linux builds.
+        x = -1-sys.maxsize
+        self.assertEqual(x >> 1, x//2)
+
+        x = int('1' * 600)
+        self.assertIsInstance(x, int)
+
+
+        self.assertRaises(TypeError, int, 1, 12)
+
+        self.assertEqual(int('0o123', 0), 83)
+        self.assertEqual(int('0x123', 16), 291)
+
+        # Bug 1679: "0x" is not a valid hex literal
+        self.assertRaises(ValueError, int, "0x", 16)
+        self.assertRaises(ValueError, int, "0x", 0)
+
+        self.assertRaises(ValueError, int, "0o", 8)
+        self.assertRaises(ValueError, int, "0o", 0)
+
+        self.assertRaises(ValueError, int, "0b", 2)
+        self.assertRaises(ValueError, int, "0b", 0)
+
+        # SF bug 1334662: int(string, base) wrong answers
+        # Various representations of 2**32 evaluated to 0
+        # rather than 2**32 in previous versions
+
+        self.assertEqual(int('100000000000000000000000000000000', 2), 4294967296)
+        self.assertEqual(int('102002022201221111211', 3), 4294967296)
+        self.assertEqual(int('10000000000000000', 4), 4294967296)
+        self.assertEqual(int('32244002423141', 5), 4294967296)
+        self.assertEqual(int('1550104015504', 6), 4294967296)
+        self.assertEqual(int('211301422354', 7), 4294967296)
+        self.assertEqual(int('40000000000', 8), 4294967296)
+        self.assertEqual(int('12068657454', 9), 4294967296)
+        self.assertEqual(int('4294967296', 10), 4294967296)
+        self.assertEqual(int('1904440554', 11), 4294967296)
+        self.assertEqual(int('9ba461594', 12), 4294967296)
+        self.assertEqual(int('535a79889', 13), 4294967296)
+        self.assertEqual(int('2ca5b7464', 14), 4294967296)
+        self.assertEqual(int('1a20dcd81', 15), 4294967296)
+        self.assertEqual(int('100000000', 16), 4294967296)
+        self.assertEqual(int('a7ffda91', 17), 4294967296)
+        self.assertEqual(int('704he7g4', 18), 4294967296)
+        self.assertEqual(int('4f5aff66', 19), 4294967296)
+        self.assertEqual(int('3723ai4g', 20), 4294967296)
+        self.assertEqual(int('281d55i4', 21), 4294967296)
+        self.assertEqual(int('1fj8b184', 22), 4294967296)
+        self.assertEqual(int('1606k7ic', 23), 4294967296)
+        self.assertEqual(int('mb994ag', 24), 4294967296)
+        self.assertEqual(int('hek2mgl', 25), 4294967296)
+        self.assertEqual(int('dnchbnm', 26), 4294967296)
+        self.assertEqual(int('b28jpdm', 27), 4294967296)
+        self.assertEqual(int('8pfgih4', 28), 4294967296)
+        self.assertEqual(int('76beigg', 29), 4294967296)
+        self.assertEqual(int('5qmcpqg', 30), 4294967296)
+        self.assertEqual(int('4q0jto4', 31), 4294967296)
+        self.assertEqual(int('4000000', 32), 4294967296)
+        self.assertEqual(int('3aokq94', 33), 4294967296)
+        self.assertEqual(int('2qhxjli', 34), 4294967296)
+        self.assertEqual(int('2br45qb', 35), 4294967296)
+        self.assertEqual(int('1z141z4', 36), 4294967296)
+
+        # tests with base 0
+        # this fails on 3.0, but in 2.x the old octal syntax is allowed
+        self.assertEqual(int(' 0o123  ', 0), 83)
+        self.assertEqual(int(' 0o123  ', 0), 83)
+        self.assertEqual(int('000', 0), 0)
+        self.assertEqual(int('0o123', 0), 83)
+        self.assertEqual(int('0x123', 0), 291)
+        self.assertEqual(int('0b100', 0), 4)
+        self.assertEqual(int(' 0O123   ', 0), 83)
+        self.assertEqual(int(' 0X123  ', 0), 291)
+        self.assertEqual(int(' 0B100 ', 0), 4)
+
+        # without base still base 10
+        self.assertEqual(int('0123'), 123)
+        self.assertEqual(int('0123', 10), 123)
+
+        # tests with prefix and base != 0
+        self.assertEqual(int('0x123', 16), 291)
+        self.assertEqual(int('0o123', 8), 83)
+        self.assertEqual(int('0b100', 2), 4)
+        self.assertEqual(int('0X123', 16), 291)
+        self.assertEqual(int('0O123', 8), 83)
+        self.assertEqual(int('0B100', 2), 4)
+
+        # the code has special checks for the first character after the
+        #  type prefix
+        self.assertRaises(ValueError, int, '0b2', 2)
+        self.assertRaises(ValueError, int, '0b02', 2)
+        self.assertRaises(ValueError, int, '0B2', 2)
+        self.assertRaises(ValueError, int, '0B02', 2)
+        self.assertRaises(ValueError, int, '0o8', 8)
+        self.assertRaises(ValueError, int, '0o08', 8)
+        self.assertRaises(ValueError, int, '0O8', 8)
+        self.assertRaises(ValueError, int, '0O08', 8)
+        self.assertRaises(ValueError, int, '0xg', 16)
+        self.assertRaises(ValueError, int, '0x0g', 16)
+        self.assertRaises(ValueError, int, '0Xg', 16)
+        self.assertRaises(ValueError, int, '0X0g', 16)
+
+        # SF bug 1334662: int(string, base) wrong answers
+        # Checks for proper evaluation of 2**32 + 1
+        self.assertEqual(int('100000000000000000000000000000001', 2), 4294967297)
+        self.assertEqual(int('102002022201221111212', 3), 4294967297)
+        self.assertEqual(int('10000000000000001', 4), 4294967297)
+        self.assertEqual(int('32244002423142', 5), 4294967297)
+        self.assertEqual(int('1550104015505', 6), 4294967297)
+        self.assertEqual(int('211301422355', 7), 4294967297)
+        self.assertEqual(int('40000000001', 8), 4294967297)
+        self.assertEqual(int('12068657455', 9), 4294967297)
+        self.assertEqual(int('4294967297', 10), 4294967297)
+        self.assertEqual(int('1904440555', 11), 4294967297)
+        self.assertEqual(int('9ba461595', 12), 4294967297)
+        self.assertEqual(int('535a7988a', 13), 4294967297)
+        self.assertEqual(int('2ca5b7465', 14), 4294967297)
+        self.assertEqual(int('1a20dcd82', 15), 4294967297)
+        self.assertEqual(int('100000001', 16), 4294967297)
+        self.assertEqual(int('a7ffda92', 17), 4294967297)
+        self.assertEqual(int('704he7g5', 18), 4294967297)
+        self.assertEqual(int('4f5aff67', 19), 4294967297)
+        self.assertEqual(int('3723ai4h', 20), 4294967297)
+        self.assertEqual(int('281d55i5', 21), 4294967297)
+        self.assertEqual(int('1fj8b185', 22), 4294967297)
+        self.assertEqual(int('1606k7id', 23), 4294967297)
+        self.assertEqual(int('mb994ah', 24), 4294967297)
+        self.assertEqual(int('hek2mgm', 25), 4294967297)
+        self.assertEqual(int('dnchbnn', 26), 4294967297)
+        self.assertEqual(int('b28jpdn', 27), 4294967297)
+        self.assertEqual(int('8pfgih5', 28), 4294967297)
+        self.assertEqual(int('76beigh', 29), 4294967297)
+        self.assertEqual(int('5qmcpqh', 30), 4294967297)
+        self.assertEqual(int('4q0jto5', 31), 4294967297)
+        self.assertEqual(int('4000001', 32), 4294967297)
+        self.assertEqual(int('3aokq95', 33), 4294967297)
+        self.assertEqual(int('2qhxjlj', 34), 4294967297)
+        self.assertEqual(int('2br45qc', 35), 4294967297)
+        self.assertEqual(int('1z141z5', 36), 4294967297)
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_underscores(self):
+        for lit in VALID_UNDERSCORE_LITERALS:
+            if any(ch in lit for ch in '.eEjJ'):
+                continue
+            self.assertEqual(int(lit, 0), eval(lit))
+            self.assertEqual(int(lit, 0), int(lit.replace('_', ''), 0))
+        for lit in INVALID_UNDERSCORE_LITERALS:
+            if any(ch in lit for ch in '.eEjJ'):
+                continue
+            self.assertRaises(ValueError, int, lit, 0)
+        # Additional test cases with bases != 0, only for the constructor:
+        self.assertEqual(int("1_00", 3), 9)
+        self.assertEqual(int("0_100"), 100)  # not valid as a literal!
+        self.assertEqual(int(b"1_00"), 100)  # byte underscore
+        self.assertRaises(ValueError, int, "_100")
+        self.assertRaises(ValueError, int, "+_100")
+        self.assertRaises(ValueError, int, "1__00")
+        self.assertRaises(ValueError, int, "100_")
+
+    @support.cpython_only
+    def test_small_ints(self):
+        # Bug #3236: Return small longs from PyLong_FromString
+        self.assertIs(int('10'), 10)
+        self.assertIs(int('-1'), -1)
+        self.assertIs(int(b'10'), 10)
+        self.assertIs(int(b'-1'), -1)
+
+    def test_no_args(self):
+        self.assertEqual(int(), 0)
+
+    def test_keyword_args(self):
+        # Test invoking int() using keyword arguments.
+        self.assertEqual(int('100', base=2), 4)
+        with self.assertRaisesRegex(TypeError, 'keyword argument'):
+            int(x=1.2)
+        with self.assertRaisesRegex(TypeError, 'keyword argument'):
+            int(x='100', base=2)
+        self.assertRaises(TypeError, int, base=10)
+        self.assertRaises(TypeError, int, base=0)
+
+    def test_int_base_limits(self):
+        """Testing the supported limits of the int() base parameter."""
+        self.assertEqual(int('0', 5), 0)
+        with self.assertRaises(ValueError):
+            int('0', 1)
+        with self.assertRaises(ValueError):
+            int('0', 37)
+        with self.assertRaises(ValueError):
+            int('0', -909)  # An old magic value base from Python 2.
+        with self.assertRaises(ValueError):
+            int('0', base=0-(2**234))
+        with self.assertRaises(ValueError):
+            int('0', base=2**234)
+        # Bases 2 through 36 are supported.
+        for base in range(2,37):
+            self.assertEqual(int('0', base=base), 0)
+
+    def test_int_base_bad_types(self):
+        """Not integer types are not valid bases; issue16772."""
+        with self.assertRaises(TypeError):
+            int('0', 5.5)
+        with self.assertRaises(TypeError):
+            int('0', 5.0)
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_int_base_indexable(self):
+        class MyIndexable(object):
+            def __init__(self, value):
+                self.value = value
+            def __index__(self):
+                return self.value
+
+        # Check out of range bases.
+        for base in 2**100, -2**100, 1, 37:
+            with self.assertRaises(ValueError):
+                int('43', base)
+
+        # Check in-range bases.
+        self.assertEqual(int('101', base=MyIndexable(2)), 5)
+        self.assertEqual(int('101', base=MyIndexable(10)), 101)
+        self.assertEqual(int('101', base=MyIndexable(36)), 1 + 36**2)
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_non_numeric_input_types(self):
+        # Test possible non-numeric types for the argument x, including
+        # subclasses of the explicitly documented accepted types.
+        class CustomStr(str): pass
+        class CustomBytes(bytes): pass
+        class CustomByteArray(bytearray): pass
+
+        factories = [
+            bytes,
+            bytearray,
+            lambda b: CustomStr(b.decode()),
+            CustomBytes,
+            CustomByteArray,
+            memoryview,
+        ]
+        try:
+            from array import array
+        except ImportError:
+            pass
+        else:
+            factories.append(lambda b: array('B', b))
+
+        for f in factories:
+            x = f(b'100')
+            with self.subTest(type(x)):
+                self.assertEqual(int(x), 100)
+                if isinstance(x, (str, bytes, bytearray)):
+                    self.assertEqual(int(x, 2), 4)
+                else:
+                    msg = "can't convert non-string"
+                    with self.assertRaisesRegex(TypeError, msg):
+                        int(x, 2)
+                with self.assertRaisesRegex(ValueError, 'invalid literal'):
+                    int(f(b'A' * 0x10))
+
+    def test_int_memoryview(self):
+        self.assertEqual(int(memoryview(b'123')[1:3]), 23)
+        self.assertEqual(int(memoryview(b'123\x00')[1:3]), 23)
+        self.assertEqual(int(memoryview(b'123 ')[1:3]), 23)
+        self.assertEqual(int(memoryview(b'123A')[1:3]), 23)
+        self.assertEqual(int(memoryview(b'1234')[1:3]), 23)
+
+    def test_string_float(self):
+        self.assertRaises(ValueError, int, '1.2')
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_intconversion(self):
+        # Test __int__()
+        class ClassicMissingMethods:
+            pass
+        self.assertRaises(TypeError, int, ClassicMissingMethods())
+
+        class MissingMethods(object):
+            pass
+        self.assertRaises(TypeError, int, MissingMethods())
+
+        class Foo0:
+            def __int__(self):
+                return 42
+
+        self.assertEqual(int(Foo0()), 42)
+
+        class Classic:
+            pass
+        for base in (object, Classic):
+            class IntOverridesTrunc(base):
+                def __int__(self):
+                    return 42
+                def __trunc__(self):
+                    return -12
+            self.assertEqual(int(IntOverridesTrunc()), 42)
+
+            class JustTrunc(base):
+                def __trunc__(self):
+                    return 42
+            self.assertEqual(int(JustTrunc()), 42)
+
+            class ExceptionalTrunc(base):
+                def __trunc__(self):
+                    1 / 0
+            with self.assertRaises(ZeroDivisionError):
+                int(ExceptionalTrunc())
+
+            for trunc_result_base in (object, Classic):
+                class Integral(trunc_result_base):
+                    def __int__(self):
+                        return 42
+
+                class TruncReturnsNonInt(base):
+                    def __trunc__(self):
+                        return Integral()
+                with self.assertWarns(DeprecationWarning):
+                    self.assertEqual(int(TruncReturnsNonInt()), 42)
+
+                class NonIntegral(trunc_result_base):
+                    def __trunc__(self):
+                        # Check that we avoid infinite recursion.
+                        return NonIntegral()
+
+                class TruncReturnsNonIntegral(base):
+                    def __trunc__(self):
+                        return NonIntegral()
+                try:
+                    int(TruncReturnsNonIntegral())
+                except TypeError as e:
+                    self.assertEqual(str(e),
+                                      "__trunc__ returned non-Integral"
+                                      " (type NonIntegral)")
+                else:
+                    self.fail("Failed to raise TypeError with %s" %
+                              ((base, trunc_result_base),))
+
+                # Regression test for bugs.python.org/issue16060.
+                class BadInt(trunc_result_base):
+                    def __int__(self):
+                        return 42.0
+
+                class TruncReturnsBadInt(base):
+                    def __trunc__(self):
+                        return BadInt()
+
+                with self.assertRaises(TypeError):
+                    int(TruncReturnsBadInt())
+
+    def test_int_subclass_with_int(self):
+        class MyInt(int):
+            def __int__(self):
+                return 42
+
+        class BadInt(int):
+            def __int__(self):
+                return 42.0
+
+        my_int = MyInt(7)
+        self.assertEqual(my_int, 7)
+        self.assertEqual(int(my_int), 42)
+
+        self.assertRaises(TypeError, int, BadInt())
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_int_returns_int_subclass(self):
+        class BadInt:
+            def __int__(self):
+                return True
+
+        class BadInt2(int):
+            def __int__(self):
+                return True
+
+        class TruncReturnsBadInt:
+            def __trunc__(self):
+                return BadInt()
+
+        class TruncReturnsIntSubclass:
+            def __trunc__(self):
+                return True
+
+        bad_int = BadInt()
+        with self.assertWarns(DeprecationWarning):
+            n = int(bad_int)
+        self.assertEqual(n, 1)
+        self.assertIs(type(n), int)
+
+        bad_int = BadInt2()
+        with self.assertWarns(DeprecationWarning):
+            n = int(bad_int)
+        self.assertEqual(n, 1)
+        self.assertIs(type(n), int)
+
+        bad_int = TruncReturnsBadInt()
+        with self.assertWarns(DeprecationWarning):
+            n = int(bad_int)
+        self.assertEqual(n, 1)
+        self.assertIs(type(n), int)
+
+        good_int = TruncReturnsIntSubclass()
+        n = int(good_int)
+        self.assertEqual(n, 1)
+        self.assertIs(type(n), int)
+        n = IntSubclass(good_int)
+        self.assertEqual(n, 1)
+        self.assertIs(type(n), IntSubclass)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_error_message(self):
+        def check(s, base=None):
+            with self.assertRaises(ValueError,
+                                   msg="int(%r, %r)" % (s, base)) as cm:
+                if base is None:
+                    int(s)
+                else:
+                    int(s, base)
+            self.assertEqual(cm.exception.args[0],
+                "invalid literal for int() with base %d: %r" %
+                (10 if base is None else base, s))
+
+        check('\xbd')
+        check('123\xbd')
+        check('  123 456  ')
+
+        check('123\x00')
+        # SF bug 1545497: embedded NULs were not detected with explicit base
+        check('123\x00', 10)
+        check('123\x00 245', 20)
+        check('123\x00 245', 16)
+        check('123\x00245', 20)
+        check('123\x00245', 16)
+        # byte string with embedded NUL
+        check(b'123\x00')
+        check(b'123\x00', 10)
+        # non-UTF-8 byte string
+        check(b'123\xbd')
+        check(b'123\xbd', 10)
+        # lone surrogate in Unicode string
+        check('123\ud800')
+        check('123\ud800', 10)
+
+    def test_issue31619(self):
+        self.assertEqual(int('1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1_0_1', 2),
+                         0b1010101010101010101010101010101)
+        self.assertEqual(int('1_2_3_4_5_6_7_0_1_2_3', 8), 0o12345670123)
+        self.assertEqual(int('1_2_3_4_5_6_7_8_9', 16), 0x123456789)
+        self.assertEqual(int('1_2_3_4_5_6_7', 32), 1144132807)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/test/test_int_literal.py b/Lib/test/test_int_literal.py
new file mode 100644
index 000000000..bf725710d
--- /dev/null
+++ b/Lib/test/test_int_literal.py
@@ -0,0 +1,143 @@
+"""Test correct treatment of hex/oct constants.
+
+This is complex because of changes due to PEP 237.
+"""
+
+import unittest
+
+class TestHexOctBin(unittest.TestCase):
+
+    def test_hex_baseline(self):
+        # A few upper/lowercase tests
+        self.assertEqual(0x0, 0X0)
+        self.assertEqual(0x1, 0X1)
+        self.assertEqual(0x123456789abcdef, 0X123456789abcdef)
+        # Baseline tests
+        self.assertEqual(0x0, 0)
+        self.assertEqual(0x10, 16)
+        self.assertEqual(0x7fffffff, 2147483647)
+        self.assertEqual(0x7fffffffffffffff, 9223372036854775807)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0x0), 0)
+        self.assertEqual(-(0x10), -16)
+        self.assertEqual(-(0x7fffffff), -2147483647)
+        self.assertEqual(-(0x7fffffffffffffff), -9223372036854775807)
+        # Ditto with a minus sign and NO parentheses
+        self.assertEqual(-0x0, 0)
+        self.assertEqual(-0x10, -16)
+        self.assertEqual(-0x7fffffff, -2147483647)
+        self.assertEqual(-0x7fffffffffffffff, -9223372036854775807)
+
+    def test_hex_unsigned(self):
+        # Positive constants
+        self.assertEqual(0x80000000, 2147483648)
+        self.assertEqual(0xffffffff, 4294967295)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0x80000000), -2147483648)
+        self.assertEqual(-(0xffffffff), -4294967295)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0x80000000, -2147483648)
+        self.assertEqual(-0xffffffff, -4294967295)
+
+        # Positive constants
+        self.assertEqual(0x8000000000000000, 9223372036854775808)
+        self.assertEqual(0xffffffffffffffff, 18446744073709551615)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0x8000000000000000), -9223372036854775808)
+        self.assertEqual(-(0xffffffffffffffff), -18446744073709551615)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0x8000000000000000, -9223372036854775808)
+        self.assertEqual(-0xffffffffffffffff, -18446744073709551615)
+
+    def test_oct_baseline(self):
+        # A few upper/lowercase tests
+        self.assertEqual(0o0, 0O0)
+        self.assertEqual(0o1, 0O1)
+        self.assertEqual(0o1234567, 0O1234567)
+        # Baseline tests
+        self.assertEqual(0o0, 0)
+        self.assertEqual(0o20, 16)
+        self.assertEqual(0o17777777777, 2147483647)
+        self.assertEqual(0o777777777777777777777, 9223372036854775807)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0o0), 0)
+        self.assertEqual(-(0o20), -16)
+        self.assertEqual(-(0o17777777777), -2147483647)
+        self.assertEqual(-(0o777777777777777777777), -9223372036854775807)
+        # Ditto with a minus sign and NO parentheses
+        self.assertEqual(-0o0, 0)
+        self.assertEqual(-0o20, -16)
+        self.assertEqual(-0o17777777777, -2147483647)
+        self.assertEqual(-0o777777777777777777777, -9223372036854775807)
+
+    def test_oct_unsigned(self):
+        # Positive constants
+        self.assertEqual(0o20000000000, 2147483648)
+        self.assertEqual(0o37777777777, 4294967295)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0o20000000000), -2147483648)
+        self.assertEqual(-(0o37777777777), -4294967295)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0o20000000000, -2147483648)
+        self.assertEqual(-0o37777777777, -4294967295)
+
+        # Positive constants
+        self.assertEqual(0o1000000000000000000000, 9223372036854775808)
+        self.assertEqual(0o1777777777777777777777, 18446744073709551615)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0o1000000000000000000000), -9223372036854775808)
+        self.assertEqual(-(0o1777777777777777777777), -18446744073709551615)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0o1000000000000000000000, -9223372036854775808)
+        self.assertEqual(-0o1777777777777777777777, -18446744073709551615)
+
+    def test_bin_baseline(self):
+        # A few upper/lowercase tests
+        self.assertEqual(0b0, 0B0)
+        self.assertEqual(0b1, 0B1)
+        self.assertEqual(0b10101010101, 0B10101010101)
+        # Baseline tests
+        self.assertEqual(0b0, 0)
+        self.assertEqual(0b10000, 16)
+        self.assertEqual(0b1111111111111111111111111111111, 2147483647)
+        self.assertEqual(0b111111111111111111111111111111111111111111111111111111111111111, 9223372036854775807)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0b0), 0)
+        self.assertEqual(-(0b10000), -16)
+        self.assertEqual(-(0b1111111111111111111111111111111), -2147483647)
+        self.assertEqual(-(0b111111111111111111111111111111111111111111111111111111111111111), -9223372036854775807)
+        # Ditto with a minus sign and NO parentheses
+        self.assertEqual(-0b0, 0)
+        self.assertEqual(-0b10000, -16)
+        self.assertEqual(-0b1111111111111111111111111111111, -2147483647)
+        self.assertEqual(-0b111111111111111111111111111111111111111111111111111111111111111, -9223372036854775807)
+
+    def test_bin_unsigned(self):
+        # Positive constants
+        self.assertEqual(0b10000000000000000000000000000000, 2147483648)
+        self.assertEqual(0b11111111111111111111111111111111, 4294967295)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0b10000000000000000000000000000000), -2147483648)
+        self.assertEqual(-(0b11111111111111111111111111111111), -4294967295)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0b10000000000000000000000000000000, -2147483648)
+        self.assertEqual(-0b11111111111111111111111111111111, -4294967295)
+
+        # Positive constants
+        self.assertEqual(0b1000000000000000000000000000000000000000000000000000000000000000, 9223372036854775808)
+        self.assertEqual(0b1111111111111111111111111111111111111111111111111111111111111111, 18446744073709551615)
+        # Ditto with a minus sign and parentheses
+        self.assertEqual(-(0b1000000000000000000000000000000000000000000000000000000000000000), -9223372036854775808)
+        self.assertEqual(-(0b1111111111111111111111111111111111111111111111111111111111111111), -18446744073709551615)
+        # Ditto with a minus sign and NO parentheses
+        # This failed in Python 2.2 through 2.2.2 and in 2.3a1
+        self.assertEqual(-0b1000000000000000000000000000000000000000000000000000000000000000, -9223372036854775808)
+        self.assertEqual(-0b1111111111111111111111111111111111111111111111111111111111111111, -18446744073709551615)
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/test/test_opcodes.py b/Lib/test/test_opcodes.py
new file mode 100644
index 000000000..d37dc6e88
--- /dev/null
+++ b/Lib/test/test_opcodes.py
@@ -0,0 +1,141 @@
+# Python test set -- part 2, opcodes
+
+import unittest
+from test import support #,ann_module
+
+class OpcodeTest(unittest.TestCase):
+
+    def test_try_inside_for_loop(self):
+        n = 0
+        for i in range(10):
+            n = n+i
+            try: 1/0
+            except NameError: pass
+            except ZeroDivisionError: pass
+            except TypeError: pass
+            try: pass
+            except: pass
+            try: pass
+            finally: pass
+            n = n+i
+        if n != 90:
+            self.fail('try inside for')
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_setup_annotations_line(self):
+        # check that SETUP_ANNOTATIONS does not create spurious line numbers
+        try:
+            with open(ann_module.__file__) as f:
+                txt = f.read()
+            co = compile(txt, ann_module.__file__, 'exec')
+            self.assertEqual(co.co_firstlineno, 3)
+        except OSError:
+            pass
+
+    def test_no_annotations_if_not_needed(self):
+        class C: pass
+        with self.assertRaises(AttributeError):
+            C.__annotations__
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_use_existing_annotations(self):
+        ns = {'__annotations__': {1: 2}}
+        exec('x: int', ns)
+        self.assertEqual(ns['__annotations__'], {'x': int, 1: 2})
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_do_not_recreate_annotations(self):
+        # Don't rely on the existence of the '__annotations__' global.
+        with support.swap_item(globals(), '__annotations__', {}):
+            del globals()['__annotations__']
+            class C:
+                del __annotations__
+                with self.assertRaises(NameError):
+                    x: int
+
+    def test_raise_class_exceptions(self):
+
+        class AClass(Exception): pass
+        class BClass(AClass): pass
+        class CClass(Exception): pass
+        class DClass(AClass):
+            def __init__(self, ignore):
+                pass
+
+        try: raise AClass()
+        except: pass
+
+        try: raise AClass()
+        except AClass: pass
+
+        try: raise BClass()
+        except AClass: pass
+
+        try: raise BClass()
+        except CClass: self.fail()
+        except: pass
+
+        a = AClass()
+        b = BClass()
+
+        try:
+            raise b
+        except AClass as v:
+            self.assertEqual(v, b)
+        else:
+            self.fail("no exception")
+
+        # not enough arguments
+        ##try:  raise BClass, a
+        ##except TypeError: pass
+        ##else: self.fail("no exception")
+
+        try:  raise DClass(a)
+        except DClass as v:
+            self.assertIsInstance(v, DClass)
+        else:
+            self.fail("no exception")
+
+    def test_compare_function_objects(self):
+
+        f = eval('lambda: None')
+        g = eval('lambda: None')
+        self.assertNotEqual(f, g)
+
+        f = eval('lambda a: a')
+        g = eval('lambda a: a')
+        self.assertNotEqual(f, g)
+
+        f = eval('lambda a=1: a')
+        g = eval('lambda a=1: a')
+        self.assertNotEqual(f, g)
+
+        f = eval('lambda: 0')
+        g = eval('lambda: 1')
+        self.assertNotEqual(f, g)
+
+        f = eval('lambda: None')
+        g = eval('lambda a: None')
+        self.assertNotEqual(f, g)
+
+        f = eval('lambda a: None')
+        g = eval('lambda b: None')
+        self.assertNotEqual(f, g)
+
+        f = eval('lambda a: None')
+        g = eval('lambda a=None: None')
+        self.assertNotEqual(f, g)
+
+        f = eval('lambda a=0: None')
+        g = eval('lambda a=1: None')
+        self.assertNotEqual(f, g)
+
+    def test_modulo_of_string_subclasses(self):
+        class MyString(str):
+            def __mod__(self, value):
+                return 42
+        self.assertEqual(MyString() % 3, 42)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/Lib/test/test_pow.py b/Lib/test/test_pow.py
new file mode 100644
index 000000000..cac1ae5ea
--- /dev/null
+++ b/Lib/test/test_pow.py
@@ -0,0 +1,123 @@
+import unittest
+
+class PowTest(unittest.TestCase):
+
+    def powtest(self, type):
+        if type != float:
+            for i in range(-1000, 1000):
+                self.assertEqual(pow(type(i), 0), 1)
+                self.assertEqual(pow(type(i), 1), type(i))
+                self.assertEqual(pow(type(0), 1), type(0))
+                self.assertEqual(pow(type(1), 1), type(1))
+
+            for i in range(-100, 100):
+                self.assertEqual(pow(type(i), 3), i*i*i)
+
+            pow2 = 1
+            for i in range(0, 31):
+                self.assertEqual(pow(2, i), pow2)
+                if i != 30 : pow2 = pow2*2
+
+            for othertype in (int,):
+                for i in list(range(-10, 0)) + list(range(1, 10)):
+                    ii = type(i)
+                    for j in range(1, 11):
+                        jj = -othertype(j)
+                        pow(ii, jj)
+
+        for othertype in int, float:
+            for i in range(1, 100):
+                zero = type(0)
+                exp = -othertype(i/10.0)
+                if exp == 0:
+                    continue
+                self.assertRaises(ZeroDivisionError, pow, zero, exp)
+
+        il, ih = -20, 20
+        jl, jh = -5,   5
+        kl, kh = -10, 10
+        asseq = self.assertEqual
+        if type == float:
+            il = 1
+            asseq = self.assertAlmostEqual
+        elif type == int:
+            jl = 0
+        elif type == int:
+            jl, jh = 0, 15
+        for i in range(il, ih+1):
+            for j in range(jl, jh+1):
+                for k in range(kl, kh+1):
+                    if k != 0:
+                        if type == float or j < 0:
+                            self.assertRaises(TypeError, pow, type(i), j, k)
+                            continue
+                        asseq(
+                            pow(type(i),j,k),
+                            pow(type(i),j)% type(k)
+                        )
+
+    def test_powint(self):
+        self.powtest(int)
+
+    def test_powfloat(self):
+        self.powtest(float)
+
+    def test_other(self):
+        # Other tests-- not very systematic
+        self.assertEqual(pow(3,3) % 8, pow(3,3,8))
+        self.assertEqual(pow(3,3) % -8, pow(3,3,-8))
+        self.assertEqual(pow(3,2) % -2, pow(3,2,-2))
+        self.assertEqual(pow(-3,3) % 8, pow(-3,3,8))
+        self.assertEqual(pow(-3,3) % -8, pow(-3,3,-8))
+        self.assertEqual(pow(5,2) % -8, pow(5,2,-8))
+
+        self.assertEqual(pow(3,3) % 8, pow(3,3,8))
+        self.assertEqual(pow(3,3) % -8, pow(3,3,-8))
+        self.assertEqual(pow(3,2) % -2, pow(3,2,-2))
+        self.assertEqual(pow(-3,3) % 8, pow(-3,3,8))
+        self.assertEqual(pow(-3,3) % -8, pow(-3,3,-8))
+        self.assertEqual(pow(5,2) % -8, pow(5,2,-8))
+
+        for i in range(-10, 11):
+            for j in range(0, 6):
+                for k in range(-7, 11):
+                    if j >= 0 and k != 0:
+                        self.assertEqual(
+                            pow(i,j) % k,
+                            pow(i,j,k)
+                        )
+                    if j >= 0 and k != 0:
+                        self.assertEqual(
+                            pow(int(i),j) % k,
+                            pow(int(i),j,k)
+                        )
+
+    def test_bug643260(self):
+        class TestRpow:
+            def __rpow__(self, other):
+                return None
+        None ** TestRpow() # Won't fail when __rpow__ invoked.  SF bug #643260.
+
+    def test_bug705231(self):
+        # -1.0 raised to an integer should never blow up.  It did if the
+        # platform pow() was buggy, and Python didn't worm around it.
+        eq = self.assertEqual
+        a = -1.0
+        # The next two tests can still fail if the platform floor()
+        # function doesn't treat all large inputs as integers
+        # test_math should also fail if that is happening
+        eq(pow(a, 1.23e167), 1.0)
+        eq(pow(a, -1.23e167), 1.0)
+        for b in range(-10, 11):
+            eq(pow(a, float(b)), b & 1 and -1.0 or 1.0)
+        for n in range(0, 100):
+            fiveto = float(5 ** n)
+            # For small n, fiveto will be odd.  Eventually we run out of
+            # mantissa bits, though, and thereafer fiveto will be even.
+            expected = fiveto % 2.0 and -1.0 or 1.0
+            eq(pow(a, fiveto), expected)
+            eq(pow(a, -fiveto), expected)
+        eq(expected, 1.0)   # else we didn't push fiveto to evenness
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Lib/test/test_raise.py b/Lib/test/test_raise.py
new file mode 100644
index 000000000..062b8fcc1
--- /dev/null
+++ b/Lib/test/test_raise.py
@@ -0,0 +1,500 @@
+# Copyright 2007 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Tests for the raise statement."""
+
+from test import support
+import sys
+import types
+import unittest
+
+
+def get_tb():
+    try:
+        raise OSError()
+    except:
+        return sys.exc_info()[2]
+
+
+class Context:
+    def __enter__(self):
+        return self
+    def __exit__(self, exc_type, exc_value, exc_tb):
+        return True
+
+
+class TestRaise(unittest.TestCase):
+    def test_invalid_reraise(self):
+        try:
+            raise
+        except RuntimeError as e:
+            self.assertIn("No active exception", str(e))
+        else:
+            self.fail("No exception raised")
+
+    def test_reraise(self):
+        try:
+            try:
+                raise IndexError()
+            except IndexError as e:
+                exc1 = e
+                raise
+        except IndexError as exc2:
+            self.assertIs(exc1, exc2)
+        else:
+            self.fail("No exception raised")
+
+    def test_except_reraise(self):
+        def reraise():
+            try:
+                raise TypeError("foo")
+            except:
+                try:
+                    raise KeyError("caught")
+                except KeyError:
+                    pass
+                raise
+        self.assertRaises(TypeError, reraise)
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_finally_reraise(self):
+        def reraise():
+            try:
+                raise TypeError("foo")
+            except:
+                try:
+                    raise KeyError("caught")
+                finally:
+                    raise
+        self.assertRaises(KeyError, reraise)
+
+    def test_nested_reraise(self):
+        def nested_reraise():
+            raise
+        def reraise():
+            try:
+                raise TypeError("foo")
+            except:
+                nested_reraise()
+        self.assertRaises(TypeError, reraise)
+
+    def test_raise_from_None(self):
+        try:
+            try:
+                raise TypeError("foo")
+            except:
+                raise ValueError() from None
+        except ValueError as e:
+            self.assertIsInstance(e.__context__, TypeError)
+            self.assertIsNone(e.__cause__)
+
+    def test_with_reraise1(self):
+        def reraise():
+            try:
+                raise TypeError("foo")
+            except:
+                with Context():
+                    pass
+                raise
+        self.assertRaises(TypeError, reraise)
+
+    def test_with_reraise2(self):
+        def reraise():
+            try:
+                raise TypeError("foo")
+            except:
+                with Context():
+                    raise KeyError("caught")
+                raise
+        self.assertRaises(TypeError, reraise)
+
+    def test_yield_reraise(self):
+        def reraise():
+            try:
+                raise TypeError("foo")
+            except:
+                yield 1
+                raise
+        g = reraise()
+        next(g)
+        self.assertRaises(TypeError, lambda: next(g))
+        self.assertRaises(StopIteration, lambda: next(g))
+
+    def test_erroneous_exception(self):
+        class MyException(Exception):
+            def __init__(self):
+                raise RuntimeError()
+
+        try:
+            raise MyException
+        except RuntimeError:
+            pass
+        else:
+            self.fail("No exception raised")
+
+    def test_new_returns_invalid_instance(self):
+        # See issue #11627.
+        class MyException(Exception):
+            def __new__(cls, *args):
+                return object()
+
+        with self.assertRaises(TypeError):
+            raise MyException
+
+    def test_assert_with_tuple_arg(self):
+        try:
+            assert False, (3,)
+        except AssertionError as e:
+            self.assertEqual(str(e), "(3,)")
+
+
+
+class TestCause(unittest.TestCase):
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def testCauseSyntax(self):
+        try:
+            try:
+                try:
+                    raise TypeError
+                except Exception:
+                    raise ValueError from None
+            except ValueError as exc:
+                self.assertIsNone(exc.__cause__)
+                self.assertTrue(exc.__suppress_context__)
+                exc.__suppress_context__ = False
+                raise exc
+        except ValueError as exc:
+            e = exc
+
+        self.assertIsNone(e.__cause__)
+        self.assertFalse(e.__suppress_context__)
+        self.assertIsInstance(e.__context__, TypeError)
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_invalid_cause(self):
+        try:
+            raise IndexError from 5
+        except TypeError as e:
+            self.assertIn("exception cause", str(e))
+        else:
+            self.fail("No exception raised")
+
+    def test_class_cause(self):
+        try:
+            raise IndexError from KeyError
+        except IndexError as e:
+            self.assertIsInstance(e.__cause__, KeyError)
+        else:
+            self.fail("No exception raised")
+
+    def test_instance_cause(self):
+        cause = KeyError()
+        try:
+            raise IndexError from cause
+        except IndexError as e:
+            self.assertIs(e.__cause__, cause)
+        else:
+            self.fail("No exception raised")
+
+    def test_erroneous_cause(self):
+        class MyException(Exception):
+            def __init__(self):
+                raise RuntimeError()
+
+        try:
+            raise IndexError from MyException
+        except RuntimeError:
+            pass
+        else:
+            self.fail("No exception raised")
+
+
+class TestTraceback(unittest.TestCase):
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_sets_traceback(self):
+        try:
+            raise IndexError()
+        except IndexError as e:
+            self.assertIsInstance(e.__traceback__, types.TracebackType)
+        else:
+            self.fail("No exception raised")
+
+    def test_accepts_traceback(self):
+        tb = get_tb()
+        try:
+            raise IndexError().with_traceback(tb)
+        except IndexError as e:
+            self.assertNotEqual(e.__traceback__, tb)
+            self.assertEqual(e.__traceback__.tb_next, tb)
+        else:
+            self.fail("No exception raised")
+
+
+class TestTracebackType(unittest.TestCase):
+
+    def raiser(self):
+        raise ValueError
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_attrs(self):
+        try:
+            self.raiser()
+        except Exception as exc:
+            tb = exc.__traceback__
+
+        self.assertIsInstance(tb.tb_next, types.TracebackType)
+        self.assertIs(tb.tb_frame, sys._getframe())
+        self.assertIsInstance(tb.tb_lasti, int)
+        self.assertIsInstance(tb.tb_lineno, int)
+
+        self.assertIs(tb.tb_next.tb_next, None)
+
+        # Invalid assignments
+        with self.assertRaises(TypeError):
+            del tb.tb_next
+
+        with self.assertRaises(TypeError):
+            tb.tb_next = "asdf"
+
+        # Loops
+        with self.assertRaises(ValueError):
+            tb.tb_next = tb
+
+        with self.assertRaises(ValueError):
+            tb.tb_next.tb_next = tb
+
+        # Valid assignments
+        tb.tb_next = None
+        self.assertIs(tb.tb_next, None)
+
+        new_tb = get_tb()
+        tb.tb_next = new_tb
+        self.assertIs(tb.tb_next, new_tb)
+
+    @unittest.skip("TODO: RUSTPYTHON")
+    def test_constructor(self):
+        other_tb = get_tb()
+        frame = sys._getframe()
+
+        tb = types.TracebackType(other_tb, frame, 1, 2)
+        self.assertEqual(tb.tb_next, other_tb)
+        self.assertEqual(tb.tb_frame, frame)
+        self.assertEqual(tb.tb_lasti, 1)
+        self.assertEqual(tb.tb_lineno, 2)
+
+        tb = types.TracebackType(None, frame, 1, 2)
+        self.assertEqual(tb.tb_next, None)
+
+        with self.assertRaises(TypeError):
+            types.TracebackType("no", frame, 1, 2)
+
+        with self.assertRaises(TypeError):
+            types.TracebackType(other_tb, "no", 1, 2)
+
+        with self.assertRaises(TypeError):
+            types.TracebackType(other_tb, frame, "no", 2)
+
+        with self.assertRaises(TypeError):
+            types.TracebackType(other_tb, frame, 1, "nuh-uh")
+
+
+class TestContext(unittest.TestCase):
+    def test_instance_context_instance_raise(self):
+        context = IndexError()
+        try:
+            try:
+                raise context
+            except:
+                raise OSError()
+        except OSError as e:
+            self.assertEqual(e.__context__, context)
+        else:
+            self.fail("No exception raised")
+
+    def test_class_context_instance_raise(self):
+        context = IndexError
+        try:
+            try:
+                raise context
+            except:
+                raise OSError()
+        except OSError as e:
+            self.assertNotEqual(e.__context__, context)
+            self.assertIsInstance(e.__context__, context)
+        else:
+            self.fail("No exception raised")
+
+    def test_class_context_class_raise(self):
+        context = IndexError
+        try:
+            try:
+                raise context
+            except:
+                raise OSError
+        except OSError as e:
+            self.assertNotEqual(e.__context__, context)
+            self.assertIsInstance(e.__context__, context)
+        else:
+            self.fail("No exception raised")
+
+    def test_c_exception_context(self):
+        try:
+            try:
+                1/0
+            except:
+                raise OSError
+        except OSError as e:
+            self.assertIsInstance(e.__context__, ZeroDivisionError)
+        else:
+            self.fail("No exception raised")
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_c_exception_raise(self):
+        try:
+            try:
+                1/0
+            except:
+                xyzzy
+        except NameError as e:
+            self.assertIsInstance(e.__context__, ZeroDivisionError)
+        else:
+            self.fail("No exception raised")
+
+    def test_noraise_finally(self):
+        try:
+            try:
+                pass
+            finally:
+                raise OSError
+        except OSError as e:
+            self.assertIsNone(e.__context__)
+        else:
+            self.fail("No exception raised")
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_raise_finally(self):
+        try:
+            try:
+                1/0
+            finally:
+                raise OSError
+        except OSError as e:
+            self.assertIsInstance(e.__context__, ZeroDivisionError)
+        else:
+            self.fail("No exception raised")
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_context_manager(self):
+        class ContextManager:
+            def __enter__(self):
+                pass
+            def __exit__(self, t, v, tb):
+                xyzzy
+        try:
+            with ContextManager():
+                1/0
+        except NameError as e:
+            self.assertIsInstance(e.__context__, ZeroDivisionError)
+        else:
+            self.fail("No exception raised")
+
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
+    def test_cycle_broken(self):
+        # Self-cycles (when re-raising a caught exception) are broken
+        try:
+            try:
+                1/0
+            except ZeroDivisionError as e:
+                raise e
+        except ZeroDivisionError as e:
+            self.assertIsNone(e.__context__)
+
+    def test_reraise_cycle_broken(self):
+        # Non-trivial context cycles (through re-raising a previous exception)
+        # are broken too.
+        try:
+            try:
+                xyzzy
+            except NameError as a:
+                try:
+                    1/0
+                except ZeroDivisionError:
+                    raise a
+        except NameError as e:
+            self.assertIsNone(e.__context__.__context__)
+
+    def test_3118(self):
+        # deleting the generator caused the __context__ to be cleared
+        def gen():
+            try:
+                yield 1
+            finally:
+                pass
+
+        def f():
+            g = gen()
+            next(g)
+            try:
+                try:
+                    raise ValueError
+                except:
+                    del g
+                    raise KeyError
+            except Exception as e:
+                self.assertIsInstance(e.__context__, ValueError)
+
+        f()
+
+    def test_3611(self):
+        # A re-raised exception in a __del__ caused the __context__
+        # to be cleared
+        class C:
+            def __del__(self):
+                try:
+                    1/0
+                except:
+                    raise
+
+        def f():
+            x = C()
+            try:
+                try:
+                    x.x
+                except AttributeError:
+                    del x
+                    raise TypeError
+            except Exception as e:
+                self.assertNotEqual(e.__context__, None)
+                self.assertIsInstance(e.__context__, AttributeError)
+
+        with support.captured_output("stderr"):
+            f()
+
+class TestRemovedFunctionality(unittest.TestCase):
+    def test_tuples(self):
+        try:
+            raise (IndexError, KeyError) # This should be a tuple!
+        except TypeError:
+            pass
+        else:
+            self.fail("No exception raised")
+
+    def test_strings(self):
+        try:
+            raise "foo"
+        except TypeError:
+            pass
+        else:
+            self.fail("No exception raised")
+
+
+if __name__ == "__main__":
+    unittest.main()