May 9, 2023 · Jan 30, 2023 · Jan 31, 2023 · Jan 31, 2023 · Jan 31, 2023 · Jan 31, 2023
diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst

   .. versionadded:: 3.12

 .. opcode:: LOAD_FAST_AND_CLEAR (var_num)

   Pushes a reference to the local ``co_varnames[var_num]`` onto the stack (or
   pushes ``NULL`` onto the stack if the local variable has not been
   initialized) and sets ``co_varnames[var_num]`` to ``NULL``.

   .. versionadded:: 3.12

 .. opcode:: STORE_FAST (var_num)

   Stores ``STACK.pop()`` into the local ``co_varnames[var_num]``.
diff --git a/Doc/whatsnew/3.12.rst b/Doc/whatsnew/3.12.rst
  In Python 3.14, the default will switch to ``'data'``.
  (Contributed by Petr Viktorin in :pep:`706`.)

 .. _whatsnew312-pep709:

 PEP 709: Comprehension inlining
 -------------------------------

 Dictionary, list, and set comprehensions are now inlined, rather than creating a
 new single-use function object for each execution of the comprehension. This
 speeds up execution of a comprehension by up to 2x.

 Comprehension iteration variables remain isolated; they don't overwrite a
 variable of the same name in the outer scope, nor are they visible after the
 comprehension. This isolation is now maintained via stack/locals manipulation,
 not via separate function scope.

 Inlining does result in a few visible behavior changes:

 * There is no longer a separate frame for the comprehension in tracebacks,
  and tracing/profiling no longer shows the comprehension as a function call.
 * Calling :func:`locals` inside a comprehension now includes variables
  from outside the comprehension, and no longer includes the synthetic ``.0``
  variable for the comprehension "argument".

 Contributed by Carl Meyer and Vladimir Matveev in :pep:`709`.

 PEP 688: Making the buffer protocol accessible in Python
 --------------------------------------------------------

diff --git a/Include/internal/pycore_code.h b/Include/internal/pycore_code.h
 // Note that these all fit within a byte, as do combinations.
 // Later, we will use the smaller numbers to differentiate the different
 // kinds of locals (e.g. pos-only arg, varkwargs, local-only).
 #define CO_FAST_HIDDEN  0x10
 #define CO_FAST_LOCAL   0x20
 #define CO_FAST_CELL    0x40
 #define CO_FAST_FREE    0x80
diff --git a/Include/internal/pycore_compile.h b/Include/internal/pycore_compile.h
    PyObject *u_varnames;  /* local variables */
    PyObject *u_cellvars;  /* cell variables */
    PyObject *u_freevars;  /* free variables */
    PyObject *u_fasthidden; /* dict; keys are names that are fast-locals only
                               temporarily within an inlined comprehension. When
                               value is True, treat as fast-local. */

    Py_ssize_t u_argcount;        /* number of arguments for block */
    Py_ssize_t u_posonlyargcount;        /* number of positional only arguments for block */
diff --git a/Include/internal/pycore_flowgraph.h b/Include/internal/pycore_flowgraph.h
 int _PyCfg_OptimizeCodeUnit(_PyCfgBuilder *g, PyObject *consts, PyObject *const_cache,
                            int code_flags, int nlocals, int nparams, int firstlineno);
 int _PyCfg_Stackdepth(_PyCfgBasicblock *entryblock, int code_flags);
 void_PyCfg_ConvertExceptionHandlersToNops(_PyCfgBasicblock *entryblock);
 void_PyCfg_ConvertPseudoOps(_PyCfgBasicblock *entryblock);
 int _PyCfg_ResolveJumps(_PyCfgBuilder *g);


diff --git a/Include/internal/pycore_opcode.h b/Include/internal/pycore_opcode.h
diff --git a/Include/internal/pycore_symtable.h b/Include/internal/pycore_symtable.h
    unsigned ste_needs_class_closure : 1; /* for class scopes, true if a
                                             closure over __class__
                                             should be created */
    unsigned ste_comp_inlined : 1; /* true if this comprehension is inlined */
    unsigned ste_comp_iter_target : 1; /* true if visiting comprehension target */
    int ste_comp_iter_expr; /* non-zero if visiting a comprehension range expression */
    int ste_lineno;          /* first line of block */
diff --git a/Include/opcode.h b/Include/opcode.h
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py
 #     Python 3.12b1 3526 (Add instrumentation support)
 #     Python 3.12b1 3527 (Add LOAD_SUPER_ATTR)
 #     Python 3.12b1 3528 (Add LOAD_SUPER_ATTR_METHOD specialization)
 #     Python 3.12b1 3529 (Inline list/dict/set comprehensions)

 #     Python 3.13 will start with 3550

 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.

 MAGIC_NUMBER = (3528).to_bytes(2, 'little') + b'\r\n'
 MAGIC_NUMBER = (3529).to_bytes(2, 'little') + b'\r\n'

 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c

diff --git a/Lib/opcode.py b/Lib/opcode.py
 jrel_op('JUMP_BACKWARD', 140)    # Number of words to skip (backwards)
 name_op('LOAD_SUPER_ATTR', 141)
 def_op('CALL_FUNCTION_EX', 142)  # Flags
 def_op('LOAD_FAST_AND_CLEAR', 143)  # Local variable number
 haslocal.append(143)

 def_op('EXTENDED_ARG', 144)
 EXTENDED_ARG = 144
 pseudo_op('LOAD_ZERO_SUPER_METHOD', 264, ['LOAD_SUPER_ATTR'])
 pseudo_op('LOAD_ZERO_SUPER_ATTR', 265, ['LOAD_SUPER_ATTR'])

 pseudo_op('STORE_FAST_MAYBE_NULL', 266, ['STORE_FAST'])

 MAX_PSEUDO_OPCODE = MIN_PSEUDO_OPCODE + len(_pseudo_ops) - 1

 del def_op, name_op, jrel_op, jabs_op, pseudo_op
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
                               and x != 50)]
            """)
        compiled_code, _ = self.check_positions_against_ast(snippet)
        compiled_code = compiled_code.co_consts[0]
        self.assertIsInstance(compiled_code, types.CodeType)
        self.assertOpcodeSourcePositionIs(compiled_code, 'LIST_APPEND',
            line=1, end_line=2, column=1, end_column=8, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
            line=1, end_line=2, column=1, end_column=8, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
            line=1, end_line=6, column=0, end_column=32, occurrence=1)

    def test_multiline_async_list_comprehension(self):
        snippet = textwrap.dedent("""\
        compiled_code, _ = self.check_positions_against_ast(snippet)
        g = {}
        eval(compiled_code, g)
        compiled_code = g['f'].__code__.co_consts[1]
        compiled_code = g['f'].__code__
        self.assertIsInstance(compiled_code, types.CodeType)
        self.assertOpcodeSourcePositionIs(compiled_code, 'LIST_APPEND',
            line=2, end_line=3, column=5, end_column=12, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
            line=2, end_line=3, column=5, end_column=12, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_CONST',
            line=2, end_line=7, column=4, end_column=36, occurrence=1)

    def test_multiline_set_comprehension(self):
                               and x != 50)}
            """)
        compiled_code, _ = self.check_positions_against_ast(snippet)
        compiled_code = compiled_code.co_consts[0]
        self.assertIsInstance(compiled_code, types.CodeType)
        self.assertOpcodeSourcePositionIs(compiled_code, 'SET_ADD',
            line=1, end_line=2, column=1, end_column=8, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
            line=1, end_line=2, column=1, end_column=8, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
            line=1, end_line=6, column=0, end_column=32, occurrence=1)

    def test_multiline_async_set_comprehension(self):
        snippet = textwrap.dedent("""\
        compiled_code, _ = self.check_positions_against_ast(snippet)
        g = {}
        eval(compiled_code, g)
        compiled_code = g['f'].__code__.co_consts[1]
        compiled_code = g['f'].__code__
        self.assertIsInstance(compiled_code, types.CodeType)
        self.assertOpcodeSourcePositionIs(compiled_code, 'SET_ADD',
            line=2, end_line=3, column=5, end_column=12, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
            line=2, end_line=3, column=5, end_column=12, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_CONST',
            line=2, end_line=7, column=4, end_column=36, occurrence=1)

    def test_multiline_dict_comprehension(self):
                               and x != 50)}
            """)
        compiled_code, _ = self.check_positions_against_ast(snippet)
        compiled_code = compiled_code.co_consts[0]
        self.assertIsInstance(compiled_code, types.CodeType)
        self.assertOpcodeSourcePositionIs(compiled_code, 'MAP_ADD',
            line=1, end_line=2, column=1, end_column=7, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
            line=1, end_line=2, column=1, end_column=7, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
            line=1, end_line=6, column=0, end_column=32, occurrence=1)

    def test_multiline_async_dict_comprehension(self):
        snippet = textwrap.dedent("""\
        compiled_code, _ = self.check_positions_against_ast(snippet)
        g = {}
        eval(compiled_code, g)
        compiled_code = g['f'].__code__.co_consts[1]
        compiled_code = g['f'].__code__
        self.assertIsInstance(compiled_code, types.CodeType)
        self.assertOpcodeSourcePositionIs(compiled_code, 'MAP_ADD',
            line=2, end_line=3, column=5, end_column=11, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
            line=2, end_line=3, column=5, end_column=11, occurrence=1)
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
        self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_CONST',
            line=2, end_line=7, column=4, end_column=36, occurrence=1)

    def test_matchcase_sequence(self):
        for source in [
            "lambda: a",
            "(a for b in c)",
            "[a for b in c]",
            "{a for b in c}",
            "{a: b for c in d}",
        ]:
            with self.subTest(source):
                code = compile(f"{source}, {source}", "<test>", "eval")
diff --git a/Lib/test/test_compiler_assemble.py b/Lib/test/test_compiler_assemble.py
            metadata.setdefault(key, key)
        for key in ['consts']:
            metadata.setdefault(key, [])
        for key in ['names', 'varnames', 'cellvars', 'freevars']:
        for key in ['names', 'varnames', 'cellvars', 'freevars', 'fasthidden']:
            metadata.setdefault(key, {})
        for key in ['argcount', 'posonlyargcount', 'kwonlyargcount']:
            metadata.setdefault(key, 0)

        expected_metadata = {}
        for key, value in metadata.items():
            if key == "fasthidden":
                # not exposed on code object
                continue
            if isinstance(value, list):
                expected_metadata[key] = tuple(value)
            elif isinstance(value, dict):
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1196,6 +1196,14 @@ iterations of the loop.

		.. versionadded:: 3.12

		.. opcode:: LOAD_FAST_AND_CLEAR (var_num)

		Pushes a reference to the local ``co_varnames[var_num]`` onto the stack (or
		pushes ``NULL`` onto the stack if the local variable has not been
		initialized) and sets ``co_varnames[var_num]`` to ``NULL``.

		.. versionadded:: 3.12

		.. opcode:: STORE_FAST (var_num)

		Stores ``STACK.pop()`` into the local ``co_varnames[var_num]``.
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -153,6 +153,30 @@ New Features
		In Python 3.14, the default will switch to ``'data'``.
		(Contributed by Petr Viktorin in :pep:`706`.)

		.. _whatsnew312-pep709:

		PEP 709: Comprehension inlining
		-------------------------------

		Dictionary, list, and set comprehensions are now inlined, rather than creating a
		new single-use function object for each execution of the comprehension. This
		speeds up execution of a comprehension by up to 2x.

		Comprehension iteration variables remain isolated; they don't overwrite a
		variable of the same name in the outer scope, nor are they visible after the
		comprehension. This isolation is now maintained via stack/locals manipulation,
		not via separate function scope.

		Inlining does result in a few visible behavior changes:

		* There is no longer a separate frame for the comprehension in tracebacks,
		and tracing/profiling no longer shows the comprehension as a function call.
		* Calling :func:`locals` inside a comprehension now includes variables
		from outside the comprehension, and no longer includes the synthetic ``.0``
		variable for the comprehension "argument".

		Contributed by Carl Meyer and Vladimir Matveev in :pep:`709`.

		PEP 688: Making the buffer protocol accessible in Python
		--------------------------------------------------------

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -131,6 +131,7 @@ struct callable_cache {
		// Note that these all fit within a byte, as do combinations.
		// Later, we will use the smaller numbers to differentiate the different
		// kinds of locals (e.g. pos-only arg, varkwargs, local-only).
		#define CO_FAST_HIDDEN 0x10
		#define CO_FAST_LOCAL 0x20
		#define CO_FAST_CELL 0x40
		#define CO_FAST_FREE 0x80
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -70,6 +70,9 @@ typedef struct {
		PyObject u_varnames; / local variables */
		PyObject u_cellvars; / cell variables */
		PyObject u_freevars; / free variables */
		PyObject u_fasthidden; / dict; keys are names that are fast-locals only
		temporarily within an inlined comprehension. When
		value is True, treat as fast-local. */

		Py_ssize_t u_argcount; /* number of arguments for block */
		Py_ssize_t u_posonlyargcount; /* number of positional only arguments for block */
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -94,7 +94,7 @@ _PyCfgInstruction* _PyCfg_BasicblockLastInstr(const _PyCfgBasicblock *b);
		int _PyCfg_OptimizeCodeUnit(_PyCfgBuilder g, PyObject consts, PyObject *const_cache,
		int code_flags, int nlocals, int nparams, int firstlineno);
		int _PyCfg_Stackdepth(_PyCfgBasicblock *entryblock, int code_flags);
		void_PyCfg_ConvertExceptionHandlersToNops(_PyCfgBasicblock *entryblock);
		void_PyCfg_ConvertPseudoOps(_PyCfgBasicblock *entryblock);
		int _PyCfg_ResolveJumps(_PyCfgBuilder *g);


Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -64,6 +64,7 @@ typedef struct _symtable_entry {
		unsigned ste_needs_class_closure : 1; /* for class scopes, true if a
		closure over __class__
		should be created */
		unsigned ste_comp_inlined : 1; /* true if this comprehension is inlined */
		unsigned ste_comp_iter_target : 1; /* true if visiting comprehension target */
		int ste_comp_iter_expr; /* non-zero if visiting a comprehension range expression */
		int ste_lineno; /* first line of block */
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -442,6 +442,7 @@ def _write_atomic(path, data, mode=0o666):
		# Python 3.12b1 3526 (Add instrumentation support)
		# Python 3.12b1 3527 (Add LOAD_SUPER_ATTR)
		# Python 3.12b1 3528 (Add LOAD_SUPER_ATTR_METHOD specialization)
		# Python 3.12b1 3529 (Inline list/dict/set comprehensions)

		# Python 3.13 will start with 3550

Expand All		@@ -458,7 +459,7 @@ def _write_atomic(path, data, mode=0o666):
		# Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
		# in PC/launcher.c must also be updated.

		MAGIC_NUMBER = (3528).to_bytes(2, 'little') + b'\r\n'
		MAGIC_NUMBER = (3529).to_bytes(2, 'little') + b'\r\n'

		_RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -198,6 +198,8 @@ def pseudo_op(name, op, real_ops):
		jrel_op('JUMP_BACKWARD', 140) # Number of words to skip (backwards)
		name_op('LOAD_SUPER_ATTR', 141)
		def_op('CALL_FUNCTION_EX', 142) # Flags
		def_op('LOAD_FAST_AND_CLEAR', 143) # Local variable number
		haslocal.append(143)

		def_op('EXTENDED_ARG', 144)
		EXTENDED_ARG = 144
Expand DownExpand Up		@@ -268,6 +270,8 @@ def pseudo_op(name, op, real_ops):
		pseudo_op('LOAD_ZERO_SUPER_METHOD', 264, ['LOAD_SUPER_ATTR'])
		pseudo_op('LOAD_ZERO_SUPER_ATTR', 265, ['LOAD_SUPER_ATTR'])

		pseudo_op('STORE_FAST_MAYBE_NULL', 266, ['STORE_FAST'])

		MAX_PSEUDO_OPCODE = MIN_PSEUDO_OPCODE + len(_pseudo_ops) - 1

		del def_op, name_op, jrel_op, jabs_op, pseudo_op
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1352,14 +1352,11 @@ def test_multiline_list_comprehension(self):
		and x != 50)]
		""")
		compiled_code, _ = self.check_positions_against_ast(snippet)
		compiled_code = compiled_code.co_consts[0]
		self.assertIsInstance(compiled_code, types.CodeType)
		self.assertOpcodeSourcePositionIs(compiled_code, 'LIST_APPEND',
		line=1, end_line=2, column=1, end_column=8, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
		line=1, end_line=2, column=1, end_column=8, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
		line=1, end_line=6, column=0, end_column=32, occurrence=1)

		def test_multiline_async_list_comprehension(self):
		snippet = textwrap.dedent("""\
Expand All		@@ -1374,13 +1371,13 @@ async def f():
		compiled_code, _ = self.check_positions_against_ast(snippet)
		g = {}
		eval(compiled_code, g)
		compiled_code = g['f'].__code__.co_consts[1]
		compiled_code = g['f'].__code__
		self.assertIsInstance(compiled_code, types.CodeType)
		self.assertOpcodeSourcePositionIs(compiled_code, 'LIST_APPEND',
		line=2, end_line=3, column=5, end_column=12, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
		line=2, end_line=3, column=5, end_column=12, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_CONST',
		line=2, end_line=7, column=4, end_column=36, occurrence=1)

		def test_multiline_set_comprehension(self):
Expand All		@@ -1393,14 +1390,11 @@ def test_multiline_set_comprehension(self):
		and x != 50)}
		""")
		compiled_code, _ = self.check_positions_against_ast(snippet)
		compiled_code = compiled_code.co_consts[0]
		self.assertIsInstance(compiled_code, types.CodeType)
		self.assertOpcodeSourcePositionIs(compiled_code, 'SET_ADD',
		line=1, end_line=2, column=1, end_column=8, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
		line=1, end_line=2, column=1, end_column=8, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
		line=1, end_line=6, column=0, end_column=32, occurrence=1)

		def test_multiline_async_set_comprehension(self):
		snippet = textwrap.dedent("""\
Expand All		@@ -1415,13 +1409,13 @@ async def f():
		compiled_code, _ = self.check_positions_against_ast(snippet)
		g = {}
		eval(compiled_code, g)
		compiled_code = g['f'].__code__.co_consts[1]
		compiled_code = g['f'].__code__
		self.assertIsInstance(compiled_code, types.CodeType)
		self.assertOpcodeSourcePositionIs(compiled_code, 'SET_ADD',
		line=2, end_line=3, column=5, end_column=12, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
		line=2, end_line=3, column=5, end_column=12, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_CONST',
		line=2, end_line=7, column=4, end_column=36, occurrence=1)

		def test_multiline_dict_comprehension(self):
Expand All		@@ -1434,14 +1428,11 @@ def test_multiline_dict_comprehension(self):
		and x != 50)}
		""")
		compiled_code, _ = self.check_positions_against_ast(snippet)
		compiled_code = compiled_code.co_consts[0]
		self.assertIsInstance(compiled_code, types.CodeType)
		self.assertOpcodeSourcePositionIs(compiled_code, 'MAP_ADD',
		line=1, end_line=2, column=1, end_column=7, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
		line=1, end_line=2, column=1, end_column=7, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
		line=1, end_line=6, column=0, end_column=32, occurrence=1)

		def test_multiline_async_dict_comprehension(self):
		snippet = textwrap.dedent("""\
Expand All		@@ -1456,13 +1447,13 @@ async def f():
		compiled_code, _ = self.check_positions_against_ast(snippet)
		g = {}
		eval(compiled_code, g)
		compiled_code = g['f'].__code__.co_consts[1]
		compiled_code = g['f'].__code__
		self.assertIsInstance(compiled_code, types.CodeType)
		self.assertOpcodeSourcePositionIs(compiled_code, 'MAP_ADD',
		line=2, end_line=3, column=5, end_column=11, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'JUMP_BACKWARD',
		line=2, end_line=3, column=5, end_column=11, occurrence=1)
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_VALUE',
		self.assertOpcodeSourcePositionIs(compiled_code, 'RETURN_CONST',
		line=2, end_line=7, column=4, end_column=36, occurrence=1)

		def test_matchcase_sequence(self):
Expand DownExpand Up		@@ -1711,9 +1702,6 @@ def test_column_offset_deduplication(self):
		for source in [
		"lambda: a",
		"(a for b in c)",
		"[a for b in c]",
		"{a for b in c}",
		"{a: b for c in d}",
		]:
		with self.subTest(source):
		code = compile(f"{source}, {source}", "<test>", "eval")
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -16,7 +16,7 @@ def complete_metadata(self, metadata, filename="myfile.py"):
		metadata.setdefault(key, key)
		for key in ['consts']:
		metadata.setdefault(key, [])
		for key in ['names', 'varnames', 'cellvars', 'freevars']:
		for key in ['names', 'varnames', 'cellvars', 'freevars', 'fasthidden']:
		metadata.setdefault(key, {})
		for key in ['argcount', 'posonlyargcount', 'kwonlyargcount']:
		metadata.setdefault(key, 0)
Expand All		@@ -33,6 +33,9 @@ def assemble_test(self, insts, metadata, expected):

		expected_metadata = {}
		for key, value in metadata.items():
		if key == "fasthidden":
		# not exposed on code object
		continue
		if isinstance(value, list):
		expected_metadata[key] = tuple(value)
		elif isinstance(value, dict):
Expand Down