dis
— Disassembler for Python bytecode¶
Source code: Lib/dis.py
The dis
module supports the analysis of CPython bytecode by
disassembling it. The CPython bytecode which this module takes as an input is
defined in the file Include/opcode.h
and used by the compiler and the
interpreter.
CPython implementation detail: Bytecode is an implementation detail of the CPython interpreter. No guarantees are made that bytecode will not be added, removed, or changed between versions of Python. Use of this module should not be considered to work across Python VMs or Python releases.
Zmienione w wersji 3.6: Use 2 bytes for each instruction. Previously the number of bytes varied by instruction.
Example: Given the function myfunc()
:
def myfunc(alist):
return len(alist)
the following command can be used to display the disassembly of
myfunc()
:
>>> dis.dis(myfunc)
2 0 LOAD_GLOBAL 0 (len)
2 LOAD_FAST 0 (alist)
4 CALL_FUNCTION 1
6 RETURN_VALUE
(The „2” is a line number).
Bytecode analysis¶
Nowe w wersji 3.4.
The bytecode analysis API allows pieces of Python code to be wrapped in a
Bytecode
object that provides easy access to details of the compiled
code.
-
class
dis.
Bytecode
(x, *, first_line=None, current_offset=None)¶ Analyse the bytecode corresponding to a function, generator, asynchronous generator, coroutine, method, string of source code, or a code object (as returned by
compile()
).This is a convenience wrapper around many of the functions listed below, most notably
get_instructions()
, as iterating over aBytecode
instance yields the bytecode operations asInstruction
instances.If first_line is not
None
, it indicates the line number that should be reported for the first source line in the disassembled code. Otherwise, the source line information (if any) is taken directly from the disassembled code object.If current_offset is not
None
, it refers to an instruction offset in the disassembled code. Setting this meansdis()
will display a „current instruction” marker against the specified opcode.-
classmethod
from_traceback
(tb)¶ Construct a
Bytecode
instance from the given traceback, setting current_offset to the instruction responsible for the exception.
-
codeobj
¶ The compiled code object.
-
first_line
¶ The first source line of the code object (if available)
-
dis
()¶ Return a formatted view of the bytecode operations (the same as printed by
dis.dis()
, but returned as a multi-line string).
-
info
()¶ Return a formatted multi-line string with detailed information about the code object, like
code_info()
.
Zmienione w wersji 3.7: This can now handle coroutine and asynchronous generator objects.
-
classmethod
Example:
>>> bytecode = dis.Bytecode(myfunc)
>>> for instr in bytecode:
... print(instr.opname)
...
LOAD_GLOBAL
LOAD_FAST
CALL_FUNCTION
RETURN_VALUE
Analysis functions¶
The dis
module also defines the following analysis functions that convert
the input directly to the desired output. They can be useful if only a single
operation is being performed, so the intermediate analysis object isn’t useful:
-
dis.
code_info
(x)¶ Return a formatted multi-line string with detailed code object information for the supplied function, generator, asynchronous generator, coroutine, method, source code string or code object.
Note that the exact contents of code info strings are highly implementation dependent and they may change arbitrarily across Python VMs or Python releases.
Nowe w wersji 3.2.
Zmienione w wersji 3.7: This can now handle coroutine and asynchronous generator objects.
-
dis.
show_code
(x, *, file=None)¶ Print detailed code object information for the supplied function, method, source code string or code object to file (or
sys.stdout
if file is not specified).This is a convenient shorthand for
print(code_info(x), file=file)
, intended for interactive exploration at the interpreter prompt.Nowe w wersji 3.2.
Zmienione w wersji 3.4: Added file parameter.
-
dis.
dis
(x=None, *, file=None, depth=None)¶ Disassemble the x object. x can denote either a module, a class, a method, a function, a generator, an asynchronous generator, a coroutine, a code object, a string of source code or a byte sequence of raw bytecode. For a module, it disassembles all functions. For a class, it disassembles all methods (including class and static methods). For a code object or sequence of raw bytecode, it prints one line per bytecode instruction. It also recursively disassembles nested code objects (the code of comprehensions, generator expressions and nested functions, and the code used for building nested classes). Strings are first compiled to code objects with the
compile()
built-in function before being disassembled. If no object is provided, this function disassembles the last traceback.The disassembly is written as text to the supplied file argument if provided and to
sys.stdout
otherwise.The maximal depth of recursion is limited by depth unless it is
None
.depth=0
means no recursion.Zmienione w wersji 3.4: Added file parameter.
Zmienione w wersji 3.7: Implemented recursive disassembling and added depth parameter.
Zmienione w wersji 3.7: This can now handle coroutine and asynchronous generator objects.
-
dis.
distb
(tb=None, *, file=None)¶ Disassemble the top-of-stack function of a traceback, using the last traceback if none was passed. The instruction causing the exception is indicated.
The disassembly is written as text to the supplied file argument if provided and to
sys.stdout
otherwise.Zmienione w wersji 3.4: Added file parameter.
-
dis.
disassemble
(code, lasti=-1, *, file=None)¶ -
dis.
disco
(code, lasti=-1, *, file=None)¶ Disassemble a code object, indicating the last instruction if lasti was provided. The output is divided in the following columns:
the line number, for the first instruction of each line
the current instruction, indicated as
-->
,a labelled instruction, indicated with
>>
,the address of the instruction,
the operation code name,
operation parameters, and
interpretation of the parameters in parentheses.
The parameter interpretation recognizes local and global variable names, constant values, branch targets, and compare operators.
The disassembly is written as text to the supplied file argument if provided and to
sys.stdout
otherwise.Zmienione w wersji 3.4: Added file parameter.
-
dis.
get_instructions
(x, *, first_line=None)¶ Return an iterator over the instructions in the supplied function, method, source code string or code object.
The iterator generates a series of
Instruction
named tuples giving the details of each operation in the supplied code.If first_line is not
None
, it indicates the line number that should be reported for the first source line in the disassembled code. Otherwise, the source line information (if any) is taken directly from the disassembled code object.Nowe w wersji 3.4.
-
dis.
findlinestarts
(code)¶ This generator function uses the
co_firstlineno
andco_lnotab
attributes of the code object code to find the offsets which are starts of lines in the source code. They are generated as(offset, lineno)
pairs. See Objects/lnotab_notes.txt for theco_lnotab
format and how to decode it.Zmienione w wersji 3.6: Line numbers can be decreasing. Before, they were always increasing.
-
dis.
findlabels
(code)¶ Detect all offsets in the raw compiled bytecode string code which are jump targets, and return a list of these offsets.
-
dis.
stack_effect
(opcode, oparg=None, *, jump=None)¶ Compute the stack effect of opcode with argument oparg.
If the code has a jump target and jump is
True
,stack_effect()
will return the stack effect of jumping. If jump isFalse
, it will return the stack effect of not jumping. And if jump isNone
(default), it will return the maximal stack effect of both cases.Nowe w wersji 3.4.
Zmienione w wersji 3.8: Added jump parameter.
Python Bytecode Instructions¶
The get_instructions()
function and Bytecode
class provide
details of bytecode instructions as Instruction
instances:
-
class
dis.
Instruction
¶ Details for a bytecode operation
-
opcode
¶ numeric code for operation, corresponding to the opcode values listed below and the bytecode values in the Opcode collections.
-
opname
¶ human readable name for operation
-
arg
¶ numeric argument to operation (if any), otherwise
None
-
argval
¶ resolved arg value (if known), otherwise same as arg
-
argrepr
¶ human readable description of operation argument
-
offset
¶ start index of operation within bytecode sequence
-
starts_line
¶ line started by this opcode (if any), otherwise
None
-
is_jump_target
¶ True
if other code jumps to here, otherwiseFalse
Nowe w wersji 3.4.
-
The Python compiler currently generates the following bytecode instructions.
General instructions
-
NOP
¶ Do nothing code. Used as a placeholder by the bytecode optimizer.
-
POP_TOP
¶ Removes the top-of-stack (TOS) item.
-
ROT_TWO
¶ Swaps the two top-most stack items.
-
ROT_THREE
¶ Lifts second and third stack item one position up, moves top down to position three.
-
ROT_FOUR
¶ Lifts second, third and fourth stack items one position up, moves top down to position four.
Nowe w wersji 3.8.
-
DUP_TOP
¶ Duplicates the reference on top of the stack.
Nowe w wersji 3.2.
-
DUP_TOP_TWO
¶ Duplicates the two references on top of the stack, leaving them in the same order.
Nowe w wersji 3.2.
Unary operations
Unary operations take the top of the stack, apply the operation, and push the result back on the stack.
-
UNARY_POSITIVE
¶ Implements
TOS = +TOS
.
-
UNARY_NEGATIVE
¶ Implements
TOS = -TOS
.
-
UNARY_NOT
¶ Implements
TOS = not TOS
.
-
UNARY_INVERT
¶ Implements
TOS = ~TOS
.
-
GET_ITER
¶ Implements
TOS = iter(TOS)
.
-
GET_YIELD_FROM_ITER
¶ If
TOS
is a generator iterator or coroutine object it is left as is. Otherwise, implementsTOS = iter(TOS)
.Nowe w wersji 3.5.
Binary operations
Binary operations remove the top of the stack (TOS) and the second top-most stack item (TOS1) from the stack. They perform the operation, and put the result back on the stack.
-
BINARY_POWER
¶ Implements
TOS = TOS1 ** TOS
.
-
BINARY_MULTIPLY
¶ Implements
TOS = TOS1 * TOS
.
-
BINARY_MATRIX_MULTIPLY
¶ Implements
TOS = TOS1 @ TOS
.Nowe w wersji 3.5.
-
BINARY_FLOOR_DIVIDE
¶ Implements
TOS = TOS1 // TOS
.
-
BINARY_TRUE_DIVIDE
¶ Implements
TOS = TOS1 / TOS
.
-
BINARY_MODULO
¶ Implements
TOS = TOS1 % TOS
.
-
BINARY_ADD
¶ Implements
TOS = TOS1 + TOS
.
-
BINARY_SUBTRACT
¶ Implements
TOS = TOS1 - TOS
.
-
BINARY_SUBSCR
¶ Implements
TOS = TOS1[TOS]
.
-
BINARY_LSHIFT
¶ Implements
TOS = TOS1 << TOS
.
-
BINARY_RSHIFT
¶ Implements
TOS = TOS1 >> TOS
.
-
BINARY_AND
¶ Implements
TOS = TOS1 & TOS
.
-
BINARY_XOR
¶ Implements
TOS = TOS1 ^ TOS
.
-
BINARY_OR
¶ Implements
TOS = TOS1 | TOS
.
In-place operations
In-place operations are like binary operations, in that they remove TOS and TOS1, and push the result back on the stack, but the operation is done in-place when TOS1 supports it, and the resulting TOS may be (but does not have to be) the original TOS1.
-
INPLACE_POWER
¶ Implements in-place
TOS = TOS1 ** TOS
.
-
INPLACE_MULTIPLY
¶ Implements in-place
TOS = TOS1 * TOS
.
-
INPLACE_MATRIX_MULTIPLY
¶ Implements in-place
TOS = TOS1 @ TOS
.Nowe w wersji 3.5.
-
INPLACE_FLOOR_DIVIDE
¶ Implements in-place
TOS = TOS1 // TOS
.
-
INPLACE_TRUE_DIVIDE
¶ Implements in-place
TOS = TOS1 / TOS
.
-
INPLACE_MODULO
¶ Implements in-place
TOS = TOS1 % TOS
.
-
INPLACE_ADD
¶ Implements in-place
TOS = TOS1 + TOS
.
-
INPLACE_SUBTRACT
¶ Implements in-place
TOS = TOS1 - TOS
.
-
INPLACE_LSHIFT
¶ Implements in-place
TOS = TOS1 << TOS
.
-
INPLACE_RSHIFT
¶ Implements in-place
TOS = TOS1 >> TOS
.
-
INPLACE_AND
¶ Implements in-place
TOS = TOS1 & TOS
.
-
INPLACE_XOR
¶ Implements in-place
TOS = TOS1 ^ TOS
.
-
INPLACE_OR
¶ Implements in-place
TOS = TOS1 | TOS
.
-
STORE_SUBSCR
¶ Implements
TOS1[TOS] = TOS2
.
-
DELETE_SUBSCR
¶ Implements
del TOS1[TOS]
.
Coroutine opcodes
-
GET_AWAITABLE
¶ Implements
TOS = get_awaitable(TOS)
, whereget_awaitable(o)
returnso
ifo
is a coroutine object or a generator object with the CO_ITERABLE_COROUTINE flag, or resolveso.__await__
.Nowe w wersji 3.5.
-
GET_AITER
¶ Implements
TOS = TOS.__aiter__()
.Nowe w wersji 3.5.
Zmienione w wersji 3.7: Returning awaitable objects from
__aiter__
is no longer supported.
-
GET_ANEXT
¶ Implements
PUSH(get_awaitable(TOS.__anext__()))
. SeeGET_AWAITABLE
for details aboutget_awaitable
Nowe w wersji 3.5.
-
END_ASYNC_FOR
¶ Terminates an
async for
loop. Handles an exception raised when awaiting a next item. If TOS isStopAsyncIteration
pop 7 values from the stack and restore the exception state using the second three of them. Otherwise re-raise the exception using the three values from the stack. An exception handler block is removed from the block stack.Nowe w wersji 3.8.
-
BEFORE_ASYNC_WITH
¶ Resolves
__aenter__
and__aexit__
from the object on top of the stack. Pushes__aexit__
and result of__aenter__()
to the stack.Nowe w wersji 3.5.
-
SETUP_ASYNC_WITH
¶ Creates a new frame object.
Nowe w wersji 3.5.
Miscellaneous opcodes
-
PRINT_EXPR
¶ Implements the expression statement for the interactive mode. TOS is removed from the stack and printed. In non-interactive mode, an expression statement is terminated with
POP_TOP
.
-
SET_ADD
(i)¶ Calls
set.add(TOS1[-i], TOS)
. Used to implement set comprehensions.
-
LIST_APPEND
(i)¶ Calls
list.append(TOS1[-i], TOS)
. Used to implement list comprehensions.
-
MAP_ADD
(i)¶ Calls
dict.__setitem__(TOS1[-i], TOS1, TOS)
. Used to implement dict comprehensions.Nowe w wersji 3.1.
Zmienione w wersji 3.8: Map value is TOS and map key is TOS1. Before, those were reversed.
For all of the SET_ADD
, LIST_APPEND
and MAP_ADD
instructions, while the added value or key/value pair is popped off, the
container object remains on the stack so that it is available for further
iterations of the loop.
-
RETURN_VALUE
¶ Returns with TOS to the caller of the function.
-
SETUP_ANNOTATIONS
¶ Checks whether
__annotations__
is defined inlocals()
, if not it is set up to an emptydict
. This opcode is only emitted if a class or module body contains variable annotations statically.Nowe w wersji 3.6.
-
IMPORT_STAR
¶ Loads all symbols not starting with
'_'
directly from the module TOS to the local namespace. The module is popped after loading all names. This opcode implementsfrom module import *
.
-
POP_BLOCK
¶ Removes one block from the block stack. Per frame, there is a stack of blocks, denoting
try
statements, and such.
-
POP_EXCEPT
¶ Removes one block from the block stack. The popped block must be an exception handler block, as implicitly created when entering an except handler. In addition to popping extraneous values from the frame stack, the last three popped values are used to restore the exception state.
-
RERAISE
¶ Re-raises the exception currently on top of the stack.
Nowe w wersji 3.9.
-
WITH_EXCEPT_START
¶ Calls the function in position 7 on the stack with the top three items on the stack as arguments. Used to implement the call
context_manager.__exit__(*exc_info())
when an exception has occurred in awith
statement.Nowe w wersji 3.9.
-
LOAD_ASSERTION_ERROR
¶ Pushes
AssertionError
onto the stack. Used by theassert
statement.Nowe w wersji 3.9.
-
LOAD_BUILD_CLASS
¶ Pushes
builtins.__build_class__()
onto the stack. It is later called byCALL_FUNCTION
to construct a class.
-
SETUP_WITH
(delta)¶ This opcode performs several operations before a with block starts. First, it loads
__exit__()
from the context manager and pushes it onto the stack for later use byWITH_EXCEPT_START
. Then,__enter__()
is called, and a finally block pointing to delta is pushed. Finally, the result of calling the__enter__()
method is pushed onto the stack. The next opcode will either ignore it (POP_TOP
), or store it in (a) variable(s) (STORE_FAST
,STORE_NAME
, orUNPACK_SEQUENCE
).Nowe w wersji 3.2.
All of the following opcodes use their arguments.
-
STORE_NAME
(namei)¶ Implements
name = TOS
. namei is the index of name in the attributeco_names
of the code object. The compiler tries to useSTORE_FAST
orSTORE_GLOBAL
if possible.
-
DELETE_NAME
(namei)¶ Implements
del name
, where namei is the index intoco_names
attribute of the code object.
-
UNPACK_SEQUENCE
(count)¶ Unpacks TOS into count individual values, which are put onto the stack right-to-left.
-
UNPACK_EX
(counts)¶ Implements assignment with a starred target: Unpacks an iterable in TOS into individual values, where the total number of values can be smaller than the number of items in the iterable: one of the new values will be a list of all leftover items.
The low byte of counts is the number of values before the list value, the high byte of counts the number of values after it. The resulting values are put onto the stack right-to-left.
-
STORE_ATTR
(namei)¶ Implements
TOS.name = TOS1
, where namei is the index of name inco_names
.
-
DELETE_ATTR
(namei)¶ Implements
del TOS.name
, using namei as index intoco_names
.
-
STORE_GLOBAL
(namei)¶ Works as
STORE_NAME
, but stores the name as a global.
-
DELETE_GLOBAL
(namei)¶ Works as
DELETE_NAME
, but deletes a global name.
-
LOAD_CONST
(consti)¶ Pushes
co_consts[consti]
onto the stack.
-
LOAD_NAME
(namei)¶ Pushes the value associated with
co_names[namei]
onto the stack.
-
BUILD_TUPLE
(count)¶ Creates a tuple consuming count items from the stack, and pushes the resulting tuple onto the stack.
-
BUILD_LIST
(count)¶ Works as
BUILD_TUPLE
, but creates a list.
-
BUILD_SET
(count)¶ Works as
BUILD_TUPLE
, but creates a set.
-
BUILD_MAP
(count)¶ Pushes a new dictionary object onto the stack. Pops
2 * count
items so that the dictionary holds count entries:{..., TOS3: TOS2, TOS1: TOS}
.Zmienione w wersji 3.5: The dictionary is created from stack items instead of creating an empty dictionary pre-sized to hold count items.
-
BUILD_CONST_KEY_MAP
(count)¶ The version of
BUILD_MAP
specialized for constant keys. Pops the top element on the stack which contains a tuple of keys, then starting fromTOS1
, pops count values to form values in the built dictionary.Nowe w wersji 3.6.
-
BUILD_STRING
(count)¶ Concatenates count strings from the stack and pushes the resulting string onto the stack.
Nowe w wersji 3.6.
-
LIST_TO_TUPLE
¶ Pops a list from the stack and pushes a tuple containing the same values.
Nowe w wersji 3.9.
-
LIST_EXTEND
(i)¶ Calls
list.extend(TOS1[-i], TOS)
. Used to build lists.Nowe w wersji 3.9.
-
SET_UPDATE
(i)¶ Calls
set.update(TOS1[-i], TOS)
. Used to build sets.Nowe w wersji 3.9.
-
DICT_UPDATE
(i)¶ Calls
dict.update(TOS1[-i], TOS)
. Used to build dicts.Nowe w wersji 3.9.
-
DICT_MERGE
¶ Like
DICT_UPDATE
but raises an exception for duplicate keys.Nowe w wersji 3.9.
-
LOAD_ATTR
(namei)¶ Replaces TOS with
getattr(TOS, co_names[namei])
.
-
COMPARE_OP
(opname)¶ Performs a Boolean operation. The operation name can be found in
cmp_op[opname]
.
-
IS_OP
(invert)¶ Performs
is
comparison, oris not
ifinvert
is 1.Nowe w wersji 3.9.
-
CONTAINS_OP
(invert)¶ Performs
in
comparison, ornot in
ifinvert
is 1.Nowe w wersji 3.9.
-
IMPORT_NAME
(namei)¶ Imports the module
co_names[namei]
. TOS and TOS1 are popped and provide the fromlist and level arguments of__import__()
. The module object is pushed onto the stack. The current namespace is not affected: for a proper import statement, a subsequentSTORE_FAST
instruction modifies the namespace.
-
IMPORT_FROM
(namei)¶ Loads the attribute
co_names[namei]
from the module found in TOS. The resulting object is pushed onto the stack, to be subsequently stored by aSTORE_FAST
instruction.
-
JUMP_FORWARD
(delta)¶ Increments bytecode counter by delta.
-
POP_JUMP_IF_TRUE
(target)¶ If TOS is true, sets the bytecode counter to target. TOS is popped.
Nowe w wersji 3.1.
-
POP_JUMP_IF_FALSE
(target)¶ If TOS is false, sets the bytecode counter to target. TOS is popped.
Nowe w wersji 3.1.
-
JUMP_IF_NOT_EXC_MATCH
(target)¶ Tests whether the second value on the stack is an exception matching TOS, and jumps if it is not. Pops two values from the stack.
Nowe w wersji 3.9.
-
JUMP_IF_TRUE_OR_POP
(target)¶ If TOS is true, sets the bytecode counter to target and leaves TOS on the stack. Otherwise (TOS is false), TOS is popped.
Nowe w wersji 3.1.
-
JUMP_IF_FALSE_OR_POP
(target)¶ If TOS is false, sets the bytecode counter to target and leaves TOS on the stack. Otherwise (TOS is true), TOS is popped.
Nowe w wersji 3.1.
-
JUMP_ABSOLUTE
(target)¶ Set bytecode counter to target.
-
FOR_ITER
(delta)¶ TOS is an iterator. Call its
__next__()
method. If this yields a new value, push it on the stack (leaving the iterator below it). If the iterator indicates it is exhausted, TOS is popped, and the byte code counter is incremented by delta.
-
LOAD_GLOBAL
(namei)¶ Loads the global named
co_names[namei]
onto the stack.
-
SETUP_FINALLY
(delta)¶ Pushes a try block from a try-finally or try-except clause onto the block stack. delta points to the finally block or the first except block.
-
LOAD_FAST
(var_num)¶ Pushes a reference to the local
co_varnames[var_num]
onto the stack.
-
STORE_FAST
(var_num)¶ Stores TOS into the local
co_varnames[var_num]
.
-
DELETE_FAST
(var_num)¶ Deletes local
co_varnames[var_num]
.
-
LOAD_CLOSURE
(i)¶ Pushes a reference to the cell contained in slot i of the cell and free variable storage. The name of the variable is
co_cellvars[i]
if i is less than the length of co_cellvars. Otherwise it isco_freevars[i - len(co_cellvars)]
.
-
LOAD_DEREF
(i)¶ Loads the cell contained in slot i of the cell and free variable storage. Pushes a reference to the object the cell contains on the stack.
-
LOAD_CLASSDEREF
(i)¶ Much like
LOAD_DEREF
but first checks the locals dictionary before consulting the cell. This is used for loading free variables in class bodies.Nowe w wersji 3.4.
-
STORE_DEREF
(i)¶ Stores TOS into the cell contained in slot i of the cell and free variable storage.
-
DELETE_DEREF
(i)¶ Empties the cell contained in slot i of the cell and free variable storage. Used by the
del
statement.Nowe w wersji 3.2.
-
RAISE_VARARGS
(argc)¶ Raises an exception using one of the 3 forms of the
raise
statement, depending on the value of argc:0:
raise
(re-raise previous exception)1:
raise TOS
(raise exception instance or type atTOS
)2:
raise TOS1 from TOS
(raise exception instance or type atTOS1
with__cause__
set toTOS
)
-
CALL_FUNCTION
(argc)¶ Calls a callable object with positional arguments. argc indicates the number of positional arguments. The top of the stack contains positional arguments, with the right-most argument on top. Below the arguments is a callable object to call.
CALL_FUNCTION
pops all arguments and the callable object off the stack, calls the callable object with those arguments, and pushes the return value returned by the callable object.Zmienione w wersji 3.6: This opcode is used only for calls with positional arguments.
-
CALL_FUNCTION_KW
(argc)¶ Calls a callable object with positional (if any) and keyword arguments. argc indicates the total number of positional and keyword arguments. The top element on the stack contains a tuple with the names of the keyword arguments, which must be strings. Below that are the values for the keyword arguments, in the order corresponding to the tuple. Below that are positional arguments, with the right-most parameter on top. Below the arguments is a callable object to call.
CALL_FUNCTION_KW
pops all arguments and the callable object off the stack, calls the callable object with those arguments, and pushes the return value returned by the callable object.Zmienione w wersji 3.6: Keyword arguments are packed in a tuple instead of a dictionary, argc indicates the total number of arguments.
-
CALL_FUNCTION_EX
(flags)¶ Calls a callable object with variable set of positional and keyword arguments. If the lowest bit of flags is set, the top of the stack contains a mapping object containing additional keyword arguments. Before the callable is called, the mapping object and iterable object are each „unpacked” and their contents passed in as keyword and positional arguments respectively.
CALL_FUNCTION_EX
pops all arguments and the callable object off the stack, calls the callable object with those arguments, and pushes the return value returned by the callable object.Nowe w wersji 3.6.
-
LOAD_METHOD
(namei)¶ Loads a method named
co_names[namei]
from the TOS object. TOS is popped. This bytecode distinguishes two cases: if TOS has a method with the correct name, the bytecode pushes the unbound method and TOS. TOS will be used as the first argument (self
) byCALL_METHOD
when calling the unbound method. Otherwise,NULL
and the object return by the attribute lookup are pushed.Nowe w wersji 3.7.
-
CALL_METHOD
(argc)¶ Calls a method. argc is the number of positional arguments. Keyword arguments are not supported. This opcode is designed to be used with
LOAD_METHOD
. Positional arguments are on top of the stack. Below them, the two items described inLOAD_METHOD
are on the stack (eitherself
and an unbound method object orNULL
and an arbitrary callable). All of them are popped and the return value is pushed.Nowe w wersji 3.7.
-
MAKE_FUNCTION
(flags)¶ Pushes a new function object on the stack. From bottom to top, the consumed stack must consist of values if the argument carries a specified flag value
0x01
a tuple of default values for positional-only and positional-or-keyword parameters in positional order0x02
a dictionary of keyword-only parameters» default values0x04
an annotation dictionary0x08
a tuple containing cells for free variables, making a closurethe code associated with the function (at TOS1)
the qualified name of the function (at TOS)
-
BUILD_SLICE
(argc)¶ Pushes a slice object on the stack. argc must be 2 or 3. If it is 2,
slice(TOS1, TOS)
is pushed; if it is 3,slice(TOS2, TOS1, TOS)
is pushed. See theslice()
built-in function for more information.
-
EXTENDED_ARG
(ext)¶ Prefixes any opcode which has an argument too big to fit into the default one byte. ext holds an additional byte which act as higher bits in the argument. For each opcode, at most three prefixal
EXTENDED_ARG
are allowed, forming an argument from two-byte to four-byte.
-
FORMAT_VALUE
(flags)¶ Used for implementing formatted literal strings (f-strings). Pops an optional fmt_spec from the stack, then a required value. flags is interpreted as follows:
(flags & 0x03) == 0x00
: value is formatted as-is.(flags & 0x03) == 0x01
: callstr()
on value before formatting it.(flags & 0x03) == 0x02
: callrepr()
on value before formatting it.(flags & 0x03) == 0x03
: callascii()
on value before formatting it.(flags & 0x04) == 0x04
: pop fmt_spec from the stack and use it, else use an empty fmt_spec.
Formatting is performed using
PyObject_Format()
. The result is pushed on the stack.Nowe w wersji 3.6.
-
HAVE_ARGUMENT
¶ This is not really an opcode. It identifies the dividing line between opcodes which don’t use their argument and those that do (
< HAVE_ARGUMENT
and>= HAVE_ARGUMENT
, respectively).Zmienione w wersji 3.6: Now every instruction has an argument, but opcodes
< HAVE_ARGUMENT
ignore it. Before, only opcodes>= HAVE_ARGUMENT
had an argument.
Opcode collections¶
These collections are provided for automatic introspection of bytecode instructions:
-
dis.
opname
¶ Sequence of operation names, indexable using the bytecode.
-
dis.
opmap
¶ Dictionary mapping operation names to bytecodes.
-
dis.
cmp_op
¶ Sequence of all compare operation names.
-
dis.
hasconst
¶ Sequence of bytecodes that access a constant.
-
dis.
hasfree
¶ Sequence of bytecodes that access a free variable (note that «free» in this context refers to names in the current scope that are referenced by inner scopes or names in outer scopes that are referenced from this scope. It does not include references to global or builtin scopes).
-
dis.
hasname
¶ Sequence of bytecodes that access an attribute by name.
-
dis.
hasjrel
¶ Sequence of bytecodes that have a relative jump target.
-
dis.
hasjabs
¶ Sequence of bytecodes that have an absolute jump target.
-
dis.
haslocal
¶ Sequence of bytecodes that access a local variable.
-
dis.
hascompare
¶ Sequence of bytecodes of Boolean operations.