dis
--- Disassembler for Python bytecode¶
Code source : Lib/dis.py
La bibliothèque dis
supporte l'analyse du bytecode CPython en le désassemblant. Le code intermédiaire CPython, que cette bibliothèque prend en paramètre, est défini dans le fichier Include/opcode.h
et est utilisé par le compilateur et l'interpréteur.
Particularité de l'implémentation CPython : Le code intermédiaire est un détail d'implémentation de l'interpréteur CPython. Il n'y a pas de garantie que le code intermédiaire sera ajouté, retiré, ou modifié dans les différentes versions de Python. L'utilisation de cette bibliothèque ne fonctionne pas nécessairement sur les machines virtuelles Python ni les différentes versions de Python.
Modifié dans la version 3.6: Utilisez 2 bits pour chaque instruction. Avant, le nombre de bits variait par instruction.
Modifié dans la version 3.10: The argument of jump, exception handling and loop instructions is now the instruction offset rather than the byte offset.
Modifié dans la version 3.11: Some instructions are accompanied by one or more inline cache entries,
which take the form of CACHE
instructions. These instructions
are hidden by default, but can be shown by passing show_caches=True
to
any dis
utility. Furthermore, the interpreter now adapts the
bytecode to specialize it for different runtime conditions. The
adaptive bytecode can be shown by passing adaptive=True
.
Modifié dans la version 3.12: The argument of a jump is the offset of the target instruction relative
to the instruction that appears immediately after the jump instruction's
CACHE
entries.
As a consequence, the presence of the CACHE
instructions is
transparent for forward jumps but needs to be taken into account when
reasoning about backward jumps.
Modifié dans la version 3.13: The output shows logical labels rather than instruction offsets
for jump targets and exception handlers. The -O
command line
option and the show_offsets
argument were added.
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 RESUME 0
3 LOAD_GLOBAL 1 (len + NULL)
LOAD_FAST 0 (alist)
CALL 1
RETURN_VALUE
(Le "2" est un numéro de ligne).
Command-line interface¶
The dis
module can be invoked as a script from the command line:
python -m dis [-h] [-C] [-O] [infile]
Les options suivantes sont acceptées :
- -h, --help¶
Display usage and exit.
- -C, --show-caches¶
Show inline caches.
- -O, --show-offsets¶
Show offsets of instructions.
If infile
is specified, its disassembled code will be written to stdout.
Otherwise, disassembly is performed on compiled source code received from stdin.
Analyse du code intermédiaire¶
Ajouté dans la version 3.4.
L'analyse de l'API code intermédiaire permet de rassembler des blocs de code en Python dans une classe Bytecode
, qui permet un accès facile aux détails du code compilé.
- class dis.Bytecode(x, *, first_line=None, current_offset=None, show_caches=False, adaptive=False, show_offsets=False)¶
Analyse le code intermédiaire correspondant à une fonction, un générateur, un générateur asynchrone, une coroutine, une méthode, une chaîne de caractères du code source, ou bien une classe (comme retourne la fonction
compile()
).Ceci est wrapper sur plusieurs fonctions de la liste ci-dessous, notamment
get_instructions()
, étant donné qu'une itération sur une instance de la classeBytecode
rend les opérations du code intermédiaire des instances deInstruction
.Si first_line ne vaut pas
None
, elle indique le nombre de la ligne qui doit être considérée comme première ligne source dans le code désassemblé. Autrement, les informations sur la ligne source sont prises directement à partir de la classe du code désassemblé.Si la valeur de current_offset est différente de
None
, c'est une référence à un offset d'une instruction dans le code désassemblé. Cela veut dire quedis()
va générer un marqueur de " l'instruction en cours" contre le code d'opération donné.If show_caches is
True
,dis()
will display inline cache entries used by the interpreter to specialize the bytecode.If adaptive is
True
,dis()
will display specialized bytecode that may be different from the original bytecode.If show_offsets is
True
,dis()
will include instruction offsets in the output.- classmethod from_traceback(tb, *, show_caches=False)¶
Construisez une instance
Bytecode
à partir de la trace d'appel, en mettant current_offet à l'instruction responsable de l'exception.
- codeobj¶
Le code compilé objet.
- first_line¶
La première ligne source du code objet (si disponible)
- dis()¶
Retourne une vue formatée des opérations du code intermédiaire (la même que celle envoyée par
dis.dis()
, mais comme une chaîne de caractères de plusieurs lignes ).
- info()¶
Retourne une chaîne de caractères de plusieurs lignes formatée avec des informations détaillées sur l'objet code comme
code_info()
.
Modifié dans la version 3.7: Cette version supporte la coroutine et les objets générateurs asynchrones.
Modifié dans la version 3.11: Added the show_caches and adaptive parameters.
Example:
>>> bytecode = dis.Bytecode(myfunc)
>>> for instr in bytecode:
... print(instr.opname)
...
RESUME
LOAD_GLOBAL
LOAD_FAST
CALL
RETURN_VALUE
Analyse de fonctions¶
La bibliothèque dis
comprend également l'analyse des fonctions suivantes, qui envoient l'entrée directement à la sortie souhaitée. Elles peuvent être utiles si il n'y a qu'une seule opération à effectuer, la représentation intermédiaire objet n'étant donc pas utile dans ce cas :
- dis.code_info(x)¶
Retourne une chaîne de caractères de plusieurs lignes formatée avec des informations détaillées sur l'objet code pour les fonctions données, les générateurs asynchrone, coroutine, la méthode, la chaine de caractères du code source ou objet.
Il est à noter que le contenu exact des chaînes de caractères figurant dans les informations du code dépendent fortement sur l'implémentation, et peuvent changer arbitrairement sous machines virtuelles Python ou les versions de Python.
Ajouté dans la version 3.2.
Modifié dans la version 3.7: Cette version supporte la coroutine et les objets générateurs asynchrones.
- dis.show_code(x, *, file=None)¶
Affiche des informations détaillées sur le code de la fonction fournie, la méthode, la chaîne de caractère du code source ou du code objet à file (ou bien
sys.stdout
si file n'est pas spécifié).Ceci est un raccourci convenable de
print(code_info(x), file=file)
, principalement fait pour l'exploration interactive sur l'invite de l'interpréteur.Ajouté dans la version 3.2.
Modifié dans la version 3.4: Ajout du paramètre file.
- dis.dis(x=None, *, file=None, depth=None, show_caches=False, adaptive=False)¶
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. These can include generator expressions, nested functions, the bodies of nested classes, and the code objects used for annotation scopes. 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.Le désassemblage est envoyé sous forme de texte à l'argument du fichier file si il est fourni, et à
sys.stdout
sinon.La profondeur maximale de récursion est limitée par depth sauf si elle correspond à
None
.depth=0
indique qu'il n'y a pas de récursion.If show_caches is
True
, this function will display inline cache entries used by the interpreter to specialize the bytecode.If adaptive is
True
, this function will display specialized bytecode that may be different from the original bytecode.Modifié dans la version 3.4: Ajout du paramètre file.
Modifié dans la version 3.7: Le désassemblage récursif a été implémenté, et le paramètre depth a été ajouté.
Modifié dans la version 3.7: Cette version supporte la coroutine et les objets générateurs asynchrones.
Modifié dans la version 3.11: Added the show_caches and adaptive parameters.
- distb(tb=None, *, file=None, show_caches=False, adaptive=False,
- show_offset=False)
Désassemble la fonction du haut de la pile des traces d'appels, en utilisant la dernière trace d'appels si rien n'a été envoyé. L'instruction à l'origine de l'exception est indiquée.
Le désassemblage est envoyé sous forme de texte à l'argument du fichier file si il est fourni, et à
sys.stdout
sinon.Modifié dans la version 3.4: Ajout du paramètre file.
Modifié dans la version 3.11: Added the show_caches and adaptive parameters.
Modifié dans la version 3.13: Added the show_offsets parameter.
- dis.disassemble(code, lasti=-1, *, file=None, show_caches=False, adaptive=False)¶
- disco(code, lasti=-1, *, file=None, show_caches=False, adaptive=False,
- show_offsets=False)
Désassemble un code objet, en indiquant la dernière instruction si lasti est fournie. La sortie est répartie sur les colonnes suivantes :
le numéro de ligne, pour la première instruction de chaque ligne
l'instruction en cours, indiquée par
-->
,une instruction libellée, indiquée par
> >
,l'adresse de l'instruction,
le nom de le code d'opération,
paramètres de l'opération, et
interprétation des paramètres entre parenthèses.
L'interprétation du paramètre reconnaît les noms des variables locales et globales, des valeurs constantes, des branchements cibles, et des opérateurs de comparaison.
Le désassemblage est envoyé sous forme de texte à l'argument du fichier file si il est fourni, et à
sys.stdout
sinon.Modifié dans la version 3.4: Ajout du paramètre file.
Modifié dans la version 3.11: Added the show_caches and adaptive parameters.
Modifié dans la version 3.13: Added the show_offsets parameter.
- dis.get_instructions(x, *, first_line=None, show_caches=False, adaptive=False)¶
Retourne un itérateur sur les instructions dans la fonction fournie, la méthode, les chaînes de caractères du code source ou objet.
Cet itérateur génère une série de n-uplets de
Instruction
qui donnent les détails de chacune des opérations dans le code fourni.Si first_line ne vaut pas
None
, elle indique le nombre de la ligne qui doit être considérée comme première ligne source dans le code désassemblé. Autrement, les informations sur la ligne source sont prises directement à partir de la classe du code désassemblé.The adaptive parameter works as it does in
dis()
.Ajouté dans la version 3.4.
Modifié dans la version 3.11: Added the show_caches and adaptive parameters.
Modifié dans la version 3.13: The show_caches parameter is deprecated and has no effect. The iterator generates the
Instruction
instances with the cache_info field populated (regardless of the value of show_caches) and it no longer generates separate items for the cache entries.
- dis.findlinestarts(code)¶
This generator function uses the
co_lines()
method 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.Modifié dans la version 3.6: Les numéros de lignes peuvent être décroissants. Avant, ils étaient toujours croissants.
Modifié dans la version 3.10: The PEP 626
co_lines()
method is used instead of theco_firstlineno
andco_lnotab
attributes of the code object.Modifié dans la version 3.13: Line numbers can be
None
for bytecode that does not map to source lines.
- 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.Ajouté dans la version 3.4.
Modifié dans la version 3.8: Added jump parameter.
Modifié dans la version 3.13: If
oparg
is omitted (orNone
), the stack effect is now returned foroparg=0
. Previously this was an error for opcodes that use their arg. It is also no longer an error to pass an integeroparg
when theopcode
does not use it; theoparg
in this case is ignored.
Les instructions du code intermédiaire en Python¶
La fonction get_instructions()
et la méthode Bytecode
fournit des détails sur le code intermédiaire des instructions comme Instruction
instances :
- class dis.Instruction¶
Détails sur le code intermédiaire de l'opération
- opcode¶
code numérique pour l'opération, correspondant aux valeurs de l'opcode ci-dessous et les valeurs du code intermédiaire dans la Opcode collections.
- opname¶
nom lisible/compréhensible de l'opération
- baseopcode¶
numeric code for the base operation if operation is specialized; otherwise equal to
opcode
- baseopname¶
human readable name for the base operation if operation is specialized; otherwise equal to
opname
- arg¶
le cas échéant, argument numérique de l'opération sinon
None
- argval¶
resolved arg value (if any), otherwise
None
- argrepr¶
human readable description of operation argument (if any), otherwise an empty string.
- offset¶
start index of operation within bytecode sequence
- start_offset¶
start index of operation within bytecode sequence, including prefixed
EXTENDED_ARG
operations if present; otherwise equal tooffset
- cache_offset¶
start index of the cache entries following the operation
- end_offset¶
end index of the cache entries following the operation
- starts_line¶
True
if this opcode starts a source line, otherwiseFalse
- line_number¶
source line number associated with this opcode (if any), otherwise
None
- is_jump_target¶
True
if other code jumps to here, otherwiseFalse
- jump_target¶
bytecode index of the jump target if this is a jump operation, otherwise
None
- positions¶
dis.Positions
object holding the start and end locations that are covered by this instruction.
Ajouté dans la version 3.4.
Modifié dans la version 3.11: Field
positions
is added.Modifié dans la version 3.13: Changed field
starts_line
.Added fields
start_offset
,cache_offset
,end_offset
,baseopname
,baseopcode
,jump_target
,oparg
,line_number
andcache_info
.
- class dis.Positions¶
In case the information is not available, some fields might be
None
.- lineno¶
- end_lineno¶
- col_offset¶
- end_col_offset¶
Ajouté dans la version 3.11.
The Python compiler currently generates the following bytecode instructions.
General instructions
In the following, We will refer to the interpreter stack as STACK
and describe
operations on it as if it was a Python list. The top of the stack corresponds to
STACK[-1]
in this language.
- NOP¶
Do nothing code. Used as a placeholder by the bytecode optimizer, and to generate line tracing events.
- POP_TOP¶
Removes the top-of-stack item:
STACK.pop()
- END_FOR¶
Removes the top-of-stack item. Equivalent to
POP_TOP
. Used to clean up at the end of loops, hence the name.Ajouté dans la version 3.12.
- END_SEND¶
Implements
del STACK[-2]
. Used to clean up when a generator exits.Ajouté dans la version 3.12.
- COPY(i)¶
Push the i-th item to the top of the stack without removing it from its original location:
assert i > 0 STACK.append(STACK[-i])
Ajouté dans la version 3.11.
- SWAP(i)¶
Swap the top of the stack with the i-th element:
STACK[-i], STACK[-1] = STACK[-1], STACK[-i]
Ajouté dans la version 3.11.
- CACHE¶
Rather than being an actual instruction, this opcode is used to mark extra space for the interpreter to cache useful data directly in the bytecode itself. It is automatically hidden by all
dis
utilities, but can be viewed withshow_caches=True
.Logically, this space is part of the preceding instruction. Many opcodes expect to be followed by an exact number of caches, and will instruct the interpreter to skip over them at runtime.
Populated caches can look like arbitrary instructions, so great care should be taken when reading or modifying raw, adaptive bytecode containing quickened data.
Ajouté dans la version 3.11.
Unary operations
Unary operations take the top of the stack, apply the operation, and push the result back on the stack.
- UNARY_NEGATIVE¶
Implements
STACK[-1] = -STACK[-1]
.
- UNARY_NOT¶
Implements
STACK[-1] = not STACK[-1]
.Modifié dans la version 3.13: This instruction now requires an exact
bool
operand.
- UNARY_INVERT¶
Implements
STACK[-1] = ~STACK[-1]
.
- GET_ITER¶
Implements
STACK[-1] = iter(STACK[-1])
.
- GET_YIELD_FROM_ITER¶
If
STACK[-1]
is a generator iterator or coroutine object it is left as is. Otherwise, implementsSTACK[-1] = iter(STACK[-1])
.Ajouté dans la version 3.5.
- TO_BOOL¶
Implements
STACK[-1] = bool(STACK[-1])
.Ajouté dans la version 3.13.
Binary and in-place operations
Binary operations remove the top two items from the stack (STACK[-1]
and
STACK[-2]
). They perform the operation, then put the result back on the stack.
In-place operations are like binary operations, but the operation is done in-place
when STACK[-2]
supports it, and the resulting STACK[-1]
may be (but does
not have to be) the original STACK[-2]
.
- BINARY_OP(op)¶
Implements the binary and in-place operators (depending on the value of op):
rhs = STACK.pop() lhs = STACK.pop() STACK.append(lhs op rhs)
Ajouté dans la version 3.11.
- BINARY_SUBSCR¶
Implements:
key = STACK.pop() container = STACK.pop() STACK.append(container[key])
- STORE_SUBSCR¶
Implements:
key = STACK.pop() container = STACK.pop() value = STACK.pop() container[key] = value
- DELETE_SUBSCR¶
Implements:
key = STACK.pop() container = STACK.pop() del container[key]
- BINARY_SLICE¶
Implements:
end = STACK.pop() start = STACK.pop() container = STACK.pop() STACK.append(container[start:end])
Ajouté dans la version 3.12.
- STORE_SLICE¶
Implements:
end = STACK.pop() start = STACK.pop() container = STACK.pop() values = STACK.pop() container[start:end] = value
Ajouté dans la version 3.12.
Coroutine opcodes
- GET_AWAITABLE(where)¶
Implements
STACK[-1] = get_awaitable(STACK[-1])
, whereget_awaitable(o)
returnso
ifo
is a coroutine object or a generator object with theCO_ITERABLE_COROUTINE
flag, or resolveso.__await__
.If the
where
operand is nonzero, it indicates where the instruction occurs:1
: After a call to__aenter__
2
: After a call to__aexit__
Ajouté dans la version 3.5.
Modifié dans la version 3.11: Previously, this instruction did not have an oparg.
- GET_AITER¶
Implements
STACK[-1] = STACK[-1].__aiter__()
.Ajouté dans la version 3.5.
Modifié dans la version 3.7: Returning awaitable objects from
__aiter__
is no longer supported.
- GET_ANEXT¶
Implement
STACK.append(get_awaitable(STACK[-1].__anext__()))
to the stack. SeeGET_AWAITABLE
for details aboutget_awaitable
.Ajouté dans la version 3.5.
- END_ASYNC_FOR¶
Terminates an
async for
loop. Handles an exception raised when awaiting a next item. The stack contains the async iterable inSTACK[-2]
and the raised exception inSTACK[-1]
. Both are popped. If the exception is notStopAsyncIteration
, it is re-raised.Ajouté dans la version 3.8.
Modifié dans la version 3.11: Exception representation on the stack now consist of one, not three, items.
- CLEANUP_THROW¶
Handles an exception raised during a
throw()
orclose()
call through the current frame. IfSTACK[-1]
is an instance ofStopIteration
, pop three values from the stack and push itsvalue
member. Otherwise, re-raiseSTACK[-1]
.Ajouté dans la version 3.12.
- BEFORE_ASYNC_WITH¶
Resolves
__aenter__
and__aexit__
fromSTACK[-1]
. Pushes__aexit__
and result of__aenter__()
to the stack:STACK.extend((__aexit__, __aenter__())
Ajouté dans la version 3.5.
Miscellaneous opcodes
- SET_ADD(i)¶
Implements:
item = STACK.pop() set.add(STACK[-i], item)
Used to implement set comprehensions.
- LIST_APPEND(i)¶
Implements:
item = STACK.pop() list.append(STACK[-i], item)
Used to implement list comprehensions.
- MAP_ADD(i)¶
Implements:
value = STACK.pop() key = STACK.pop() dict.__setitem__(STACK[-i], key, value)
Used to implement dict comprehensions.
Ajouté dans la version 3.1.
Modifié dans la version 3.8: Map value is
STACK[-1]
and map key isSTACK[-2]
. 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
STACK[-1]
to the caller of the function.
- RETURN_CONST(consti)¶
Returns with
co_consts[consti]
to the caller of the function.Ajouté dans la version 3.12.
- YIELD_VALUE¶
Yields
STACK.pop()
from a generator.Modifié dans la version 3.11: oparg set to be the stack depth.
Modifié dans la version 3.12: oparg set to be the exception block depth, for efficient closing of generators.
Modifié dans la version 3.13: oparg is
1
if this instruction is part of a yield-from or await, and0
otherwise.
- 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.Ajouté dans la version 3.6.
- POP_EXCEPT¶
Pops a value from the stack, which is used to restore the exception state.
Modifié dans la version 3.11: Exception representation on the stack now consist of one, not three, items.
- RERAISE¶
Re-raises the exception currently on top of the stack. If oparg is non-zero, pops an additional value from the stack which is used to set
f_lasti
of the current frame.Ajouté dans la version 3.9.
Modifié dans la version 3.11: Exception representation on the stack now consist of one, not three, items.
- PUSH_EXC_INFO¶
Pops a value from the stack. Pushes the current exception to the top of the stack. Pushes the value originally popped back to the stack. Used in exception handlers.
Ajouté dans la version 3.11.
- CHECK_EXC_MATCH¶
Performs exception matching for
except
. Tests whether theSTACK[-2]
is an exception matchingSTACK[-1]
. PopsSTACK[-1]
and pushes the boolean result of the test.Ajouté dans la version 3.11.
- CHECK_EG_MATCH¶
Performs exception matching for
except*
. Appliessplit(STACK[-1])
on the exception group representingSTACK[-2]
.In case of a match, pops two items from the stack and pushes the non-matching subgroup (
None
in case of full match) followed by the matching subgroup. When there is no match, pops one item (the match type) and pushesNone
.Ajouté dans la version 3.11.
- WITH_EXCEPT_START¶
Calls the function in position 4 on the stack with arguments (type, val, tb) representing the exception at the top of the stack. Used to implement the call
context_manager.__exit__(*exc_info())
when an exception has occurred in awith
statement.Ajouté dans la version 3.9.
Modifié dans la version 3.11: The
__exit__
function is in position 4 of the stack rather than 7. Exception representation on the stack now consist of one, not three, items.
- LOAD_ASSERTION_ERROR¶
Pushes
AssertionError
onto the stack. Used by theassert
statement.Ajouté dans la version 3.9.
- LOAD_BUILD_CLASS¶
Pushes
builtins.__build_class__()
onto the stack. It is later called to construct a class.
- BEFORE_WITH¶
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. Finally, the result of calling the__enter__()
method is pushed onto the stack.Ajouté dans la version 3.11.
- GET_LEN¶
Perform
STACK.append(len(STACK[-1]))
. Used inmatch
statements where comparison with structure of pattern is needed.Ajouté dans la version 3.10.
- MATCH_MAPPING¶
If
STACK[-1]
is an instance ofcollections.abc.Mapping
(or, more technically: if it has thePy_TPFLAGS_MAPPING
flag set in itstp_flags
), pushTrue
onto the stack. Otherwise, pushFalse
.Ajouté dans la version 3.10.
- MATCH_SEQUENCE¶
If
STACK[-1]
is an instance ofcollections.abc.Sequence
and is not an instance ofstr
/bytes
/bytearray
(or, more technically: if it has thePy_TPFLAGS_SEQUENCE
flag set in itstp_flags
), pushTrue
onto the stack. Otherwise, pushFalse
.Ajouté dans la version 3.10.
- MATCH_KEYS¶
STACK[-1]
is a tuple of mapping keys, andSTACK[-2]
is the match subject. IfSTACK[-2]
contains all of the keys inSTACK[-1]
, push atuple
containing the corresponding values. Otherwise, pushNone
.Ajouté dans la version 3.10.
Modifié dans la version 3.11: Previously, this instruction also pushed a boolean value indicating success (
True
) or failure (False
).
- STORE_NAME(namei)¶
Implements
name = STACK.pop()
. 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
STACK[-1]
into count individual values, which are put onto the stack right-to-left. Require there to be exactly count values.:assert(len(STACK[-1]) == count) STACK.extend(STACK.pop()[:-count-1:-1])
- UNPACK_EX(counts)¶
Implements assignment with a starred target: Unpacks an iterable in
STACK[-1]
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 number of values before and after the list value is limited to 255.
The number of values before the list value is encoded in the argument of the opcode. The number of values after the list if any is encoded using an
EXTENDED_ARG
. As a consequence, the argument can be seen as a two bytes values where 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 extracted values are put onto the stack right-to-left, i.e.
a, *b, c = d
will be stored after execution asSTACK.extend((a, b, c))
.
- STORE_ATTR(namei)¶
Implements:
obj = STACK.pop() value = STACK.pop() obj.name = value
where namei is the index of name in
co_names
of the code object.
- DELETE_ATTR(namei)¶
Implements:
obj = STACK.pop() del obj.name
where namei is the index of name into
co_names
of the code object.
- 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. The name is looked up within the locals, then the globals, then the builtins.
- LOAD_LOCALS¶
Pushes a reference to the locals dictionary onto the stack. This is used to prepare namespace dictionaries for
LOAD_FROM_DICT_OR_DEREF
andLOAD_FROM_DICT_OR_GLOBALS
.Ajouté dans la version 3.12.
- LOAD_FROM_DICT_OR_GLOBALS(i)¶
Pops a mapping off the stack and looks up the value for
co_names[namei]
. If the name is not found there, looks it up in the globals and then the builtins, similar toLOAD_GLOBAL
. This is used for loading global variables in annotation scopes within class bodies.Ajouté dans la version 3.12.
- BUILD_TUPLE(count)¶
Creates a tuple consuming count items from the stack, and pushes the resulting tuple onto the stack:
if count == 0: value = () else: value = tuple(STACK[-count:]) STACK = STACK[:-count] STACK.append(value)
- 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:{..., STACK[-4]: STACK[-3], STACK[-2]: STACK[-1]}
.Modifié dans la version 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 fromSTACK[-2]
, pops count values to form values in the built dictionary.Ajouté dans la version 3.6.
- BUILD_STRING(count)¶
Concatenates count strings from the stack and pushes the resulting string onto the stack.
Ajouté dans la version 3.6.
- LIST_EXTEND(i)¶
Implements:
seq = STACK.pop() list.extend(STACK[-i], seq)
Used to build lists.
Ajouté dans la version 3.9.
- SET_UPDATE(i)¶
Implements:
seq = STACK.pop() set.update(STACK[-i], seq)
Used to build sets.
Ajouté dans la version 3.9.
- DICT_UPDATE(i)¶
Implements:
map = STACK.pop() dict.update(STACK[-i], map)
Used to build dicts.
Ajouté dans la version 3.9.
- DICT_MERGE(i)¶
Like
DICT_UPDATE
but raises an exception for duplicate keys.Ajouté dans la version 3.9.
- LOAD_ATTR(namei)¶
If the low bit of
namei
is not set, this replacesSTACK[-1]
withgetattr(STACK[-1], co_names[namei>>1])
.If the low bit of
namei
is set, this will attempt to load a method namedco_names[namei>>1]
from theSTACK[-1]
object.STACK[-1]
is popped. This bytecode distinguishes two cases: ifSTACK[-1]
has a method with the correct name, the bytecode pushes the unbound method andSTACK[-1]
.STACK[-1]
will be used as the first argument (self
) byCALL
orCALL_KW
when calling the unbound method. Otherwise,NULL
and the object returned by the attribute lookup are pushed.Modifié dans la version 3.12: If the low bit of
namei
is set, then aNULL
orself
is pushed to the stack before the attribute or unbound method respectively.
- LOAD_SUPER_ATTR(namei)¶
This opcode implements
super()
, both in its zero-argument and two-argument forms (e.g.super().method()
,super().attr
andsuper(cls, self).method()
,super(cls, self).attr
).It pops three values from the stack (from top of stack down):
self
: the first argument to the current methodcls
: the class within which the current method was definedthe global
super
With respect to its argument, it works similarly to
LOAD_ATTR
, except thatnamei
is shifted left by 2 bits instead of 1.The low bit of
namei
signals to attempt a method load, as withLOAD_ATTR
, which results in pushingNULL
and the loaded method. When it is unset a single value is pushed to the stack.The second-low bit of
namei
, if set, means that this was a two-argument call tosuper()
(unset means zero-argument).Ajouté dans la version 3.12.
- COMPARE_OP(opname)¶
Performs a Boolean operation. The operation name can be found in
cmp_op[opname >> 5]
. If the fifth-lowest bit ofopname
is set (opname & 16
), the result should be coerced tobool
.Modifié dans la version 3.13: The fifth-lowest bit of the oparg now indicates a forced conversion to
bool
.
- IS_OP(invert)¶
Performs
is
comparison, oris not
ifinvert
is 1.Ajouté dans la version 3.9.
- CONTAINS_OP(invert)¶
Performs
in
comparison, ornot in
ifinvert
is 1.Ajouté dans la version 3.9.
- IMPORT_NAME(namei)¶
Imports the module
co_names[namei]
.STACK[-1]
andSTACK[-2]
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 inSTACK[-1]
. The resulting object is pushed onto the stack, to be subsequently stored by aSTORE_FAST
instruction.
- JUMP_FORWARD(delta)¶
Increments bytecode counter by delta.
- JUMP_BACKWARD(delta)¶
Decrements bytecode counter by delta. Checks for interrupts.
Ajouté dans la version 3.11.
- JUMP_BACKWARD_NO_INTERRUPT(delta)¶
Decrements bytecode counter by delta. Does not check for interrupts.
Ajouté dans la version 3.11.
- POP_JUMP_IF_TRUE(delta)¶
If
STACK[-1]
is true, increments the bytecode counter by delta.STACK[-1]
is popped.Modifié dans la version 3.11: The oparg is now a relative delta rather than an absolute target. This opcode is a pseudo-instruction, replaced in final bytecode by the directed versions (forward/backward).
Modifié dans la version 3.12: This is no longer a pseudo-instruction.
Modifié dans la version 3.13: This instruction now requires an exact
bool
operand.
- POP_JUMP_IF_FALSE(delta)¶
If
STACK[-1]
is false, increments the bytecode counter by delta.STACK[-1]
is popped.Modifié dans la version 3.11: The oparg is now a relative delta rather than an absolute target. This opcode is a pseudo-instruction, replaced in final bytecode by the directed versions (forward/backward).
Modifié dans la version 3.12: This is no longer a pseudo-instruction.
Modifié dans la version 3.13: This instruction now requires an exact
bool
operand.
- POP_JUMP_IF_NOT_NONE(delta)¶
If
STACK[-1]
is notNone
, increments the bytecode counter by delta.STACK[-1]
is popped.This opcode is a pseudo-instruction, replaced in final bytecode by the directed versions (forward/backward).
Ajouté dans la version 3.11.
Modifié dans la version 3.12: This is no longer a pseudo-instruction.
- POP_JUMP_IF_NONE(delta)¶
If
STACK[-1]
isNone
, increments the bytecode counter by delta.STACK[-1]
is popped.This opcode is a pseudo-instruction, replaced in final bytecode by the directed versions (forward/backward).
Ajouté dans la version 3.11.
Modifié dans la version 3.12: This is no longer a pseudo-instruction.
- FOR_ITER(delta)¶
STACK[-1]
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 then the byte code counter is incremented by delta.Modifié dans la version 3.12: Up until 3.11 the iterator was popped when it was exhausted.
- LOAD_GLOBAL(namei)¶
Loads the global named
co_names[namei>>1]
onto the stack.Modifié dans la version 3.11: If the low bit of
namei
is set, then aNULL
is pushed to the stack before the global variable.
- LOAD_FAST(var_num)¶
Pushes a reference to the local
co_varnames[var_num]
onto the stack.Modifié dans la version 3.12: This opcode is now only used in situations where the local variable is guaranteed to be initialized. It cannot raise
UnboundLocalError
.
- LOAD_FAST_CHECK(var_num)¶
Pushes a reference to the local
co_varnames[var_num]
onto the stack, raising anUnboundLocalError
if the local variable has not been initialized.Ajouté dans la version 3.12.
- LOAD_FAST_AND_CLEAR(var_num)¶
Pushes a reference to the local
co_varnames[var_num]
onto the stack (or pushesNULL
onto the stack if the local variable has not been initialized) and setsco_varnames[var_num]
toNULL
.Ajouté dans la version 3.12.
- STORE_FAST(var_num)¶
Stores
STACK.pop()
into the localco_varnames[var_num]
.
- DELETE_FAST(var_num)¶
Deletes local
co_varnames[var_num]
.
- MAKE_CELL(i)¶
Creates a new cell in slot
i
. If that slot is nonempty then that value is stored into the new cell.Ajouté dans la version 3.11.
- LOAD_DEREF(i)¶
Loads the cell contained in slot
i
of the "fast locals" storage. Pushes a reference to the object the cell contains on the stack.Modifié dans la version 3.11:
i
is no longer offset by the length ofco_varnames
.
- LOAD_FROM_DICT_OR_DEREF(i)¶
Pops a mapping off the stack and looks up the name associated with slot
i
of the "fast locals" storage in this mapping. If the name is not found there, loads it from the cell contained in sloti
, similar toLOAD_DEREF
. This is used for loading closure variables in class bodies (which previously usedLOAD_CLASSDEREF
) and in annotation scopes within class bodies.Ajouté dans la version 3.12.
- STORE_DEREF(i)¶
Stores
STACK.pop()
into the cell contained in sloti
of the "fast locals" storage.Modifié dans la version 3.11:
i
is no longer offset by the length ofco_varnames
.
- DELETE_DEREF(i)¶
Empties the cell contained in slot
i
of the "fast locals" storage. Used by thedel
statement.Ajouté dans la version 3.2.
Modifié dans la version 3.11:
i
is no longer offset by the length ofco_varnames
.
- COPY_FREE_VARS(n)¶
Copies the
n
free (closure) variables from the closure into the frame. Removes the need for special code on the caller's side when calling closures.Ajouté dans la version 3.11.
- 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 STACK[-1]
(raise exception instance or type atSTACK[-1]
)2:
raise STACK[-2] from STACK[-1]
(raise exception instance or type atSTACK[-2]
with__cause__
set toSTACK[-1]
)
- CALL(argc)¶
Calls a callable object with the number of arguments specified by
argc
. On the stack are (in ascending order):The callable
self
orNULL
The remaining positional arguments
argc
is the total of the positional arguments, excludingself
.CALL
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.Ajouté dans la version 3.11.
Modifié dans la version 3.13: The callable now always appears at the same position on the stack.
Modifié dans la version 3.13: Calls with keyword arguments are now handled by
CALL_KW
.
- CALL_KW(argc)¶
Calls a callable object with the number of arguments specified by
argc
, including one or more named arguments. On the stack are (in ascending order):The callable
self
orNULL
The remaining positional arguments
The named arguments
A
tuple
of keyword argument names
argc
is the total of the positional and named arguments, excludingself
. The length of the tuple of keyword argument names is the number of named arguments.CALL_KW
pops all arguments, the keyword names, and the callable object off the stack, calls the callable object with those arguments, and pushes the return value returned by the callable object.Ajouté dans la version 3.13.
- 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.Ajouté dans la version 3.6.
- PUSH_NULL¶
Pushes a
NULL
to the stack. Used in the call sequence to match theNULL
pushed byLOAD_METHOD
for non-method calls.Ajouté dans la version 3.11.
- MAKE_FUNCTION¶
Pushes a new function object on the stack built from the code object at
STACK[-1]
.Modifié dans la version 3.10: Flag value
0x04
is a tuple of strings instead of dictionaryModifié dans la version 3.11: Qualified name at
STACK[-1]
was removed.Modifié dans la version 3.13: Extra function attributes on the stack, signaled by oparg flags, were removed. They now use
SET_FUNCTION_ATTRIBUTE
.
- SET_FUNCTION_ATTRIBUTE(flag)¶
Sets an attribute on a function object. Expects the function at
STACK[-1]
and the attribute value to set atSTACK[-2]
; consumes both and leaves the function atSTACK[-1]
. The flag determines which attribute to set: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
a tuple of strings containing parameters' annotations0x08
a tuple containing cells for free variables, making a closure
Ajouté dans la version 3.13.
- BUILD_SLICE(argc)¶
Pushes a slice object on the stack. argc must be 2 or 3. If it is 2, implements:
end = STACK.pop() start = STACK.pop() STACK.append(slice(start, end))
if it is 3, implements:
step = STACK.pop() end = STACK.pop() start = STACK.pop() STACK.append(slice(start, end, step))
See the
slice()
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.
- CONVERT_VALUE(oparg)¶
Convert value to a string, depending on
oparg
:value = STACK.pop() result = func(value) STACK.append(result)
Used for implementing formatted literal strings (f-strings).
Ajouté dans la version 3.13.
- FORMAT_SIMPLE¶
Formats the value on top of stack:
value = STACK.pop() result = value.__format__("") STACK.append(result)
Used for implementing formatted literal strings (f-strings).
Ajouté dans la version 3.13.
- FORMAT_WITH_SPEC¶
Formats the given value with the given format spec:
spec = STACK.pop() value = STACK.pop() result = value.__format__(spec) STACK.append(result)
Used for implementing formatted literal strings (f-strings).
Ajouté dans la version 3.13.
- MATCH_CLASS(count)¶
STACK[-1]
is a tuple of keyword attribute names,STACK[-2]
is the class being matched against, andSTACK[-3]
is the match subject. count is the number of positional sub-patterns.Pop
STACK[-1]
,STACK[-2]
, andSTACK[-3]
. IfSTACK[-3]
is an instance ofSTACK[-2]
and has the positional and keyword attributes required by count andSTACK[-1]
, push a tuple of extracted attributes. Otherwise, pushNone
.Ajouté dans la version 3.10.
Modifié dans la version 3.11: Previously, this instruction also pushed a boolean value indicating success (
True
) or failure (False
).
- RESUME(context)¶
A no-op. Performs internal tracing, debugging and optimization checks.
The
context
oparand consists of two parts. The lowest two bits indicate where theRESUME
occurs:0
The start of a function, which is neither a generator, coroutine nor an async generator1
After ayield
expression2
After ayield from
expression3
After anawait
expression
The next bit is
1
if the RESUME is at except-depth1
, and0
otherwise.Ajouté dans la version 3.11.
Modifié dans la version 3.13: The oparg value changed to include information about except-depth
- RETURN_GENERATOR¶
Create a generator, coroutine, or async generator from the current frame. Used as first opcode of in code object for the above mentioned callables. Clear the current frame and return the newly created generator.
Ajouté dans la version 3.11.
- SEND(delta)¶
Equivalent to
STACK[-1] = STACK[-2].send(STACK[-1])
. Used inyield from
andawait
statements.If the call raises
StopIteration
, pop the top value from the stack, push the exception'svalue
attribute, and increment the bytecode counter by delta.Ajouté dans la version 3.11.
- HAVE_ARGUMENT¶
This is not really an opcode. It identifies the dividing line between opcodes in the range [0,255] which don't use their argument and those that do (
< HAVE_ARGUMENT
and>= HAVE_ARGUMENT
, respectively).If your application uses pseudo instructions or specialized instructions, use the
hasarg
collection instead.Modifié dans la version 3.6: Now every instruction has an argument, but opcodes
< HAVE_ARGUMENT
ignore it. Before, only opcodes>= HAVE_ARGUMENT
had an argument.Modifié dans la version 3.12: Pseudo instructions were added to the
dis
module, and for them it is not true that comparison withHAVE_ARGUMENT
indicates whether they use their arg.Obsolète depuis la version 3.13: Use
hasarg
instead.
- CALL_INTRINSIC_1¶
Calls an intrinsic function with one argument. Passes
STACK[-1]
as the argument and setsSTACK[-1]
to the result. Used to implement functionality that is not performance critical.The operand determines which intrinsic function is called:
Operand
Description
INTRINSIC_1_INVALID
Not valid
INTRINSIC_PRINT
Prints the argument to standard out. Used in the REPL.
INTRINSIC_IMPORT_STAR
Performs
import *
for the named module.INTRINSIC_STOPITERATION_ERROR
Extracts the return value from a
StopIteration
exception.INTRINSIC_ASYNC_GEN_WRAP
Wraps an async generator value
INTRINSIC_UNARY_POSITIVE
Performs the unary
+
operationINTRINSIC_LIST_TO_TUPLE
Converts a list to a tuple
INTRINSIC_TYPEVAR
Creates a
typing.TypeVar
INTRINSIC_PARAMSPEC
Creates a
typing.ParamSpec
INTRINSIC_TYPEVARTUPLE
Creates a
typing.TypeVarTuple
INTRINSIC_SUBSCRIPT_GENERIC
Returns
typing.Generic
subscripted with the argumentINTRINSIC_TYPEALIAS
Creates a
typing.TypeAliasType
; used in thetype
statement. The argument is a tuple of the type alias's name, type parameters, and value.Ajouté dans la version 3.12.
- CALL_INTRINSIC_2¶
Calls an intrinsic function with two arguments. Used to implement functionality that is not performance critical:
arg2 = STACK.pop() arg1 = STACK.pop() result = intrinsic2(arg1, arg2) STACK.append(result)
The operand determines which intrinsic function is called:
Operand
Description
INTRINSIC_2_INVALID
Not valid
INTRINSIC_PREP_RERAISE_STAR
Calculates the
ExceptionGroup
to raise from atry-except*
.INTRINSIC_TYPEVAR_WITH_BOUND
Creates a
typing.TypeVar
with a bound.INTRINSIC_TYPEVAR_WITH_CONSTRAINTS
Creates a
typing.TypeVar
with constraints.INTRINSIC_SET_FUNCTION_TYPE_PARAMS
Sets the
__type_params__
attribute of a function.Ajouté dans la version 3.12.
Pseudo-instructions
These opcodes do not appear in Python bytecode. They are used by the compiler but are replaced by real opcodes or removed before bytecode is generated.
- SETUP_FINALLY(target)¶
Set up an exception handler for the following code block. If an exception occurs, the value stack level is restored to its current state and control is transferred to the exception handler at
target
.
- SETUP_CLEANUP(target)¶
Like
SETUP_FINALLY
, but in case of an exception also pushes the last instruction (lasti
) to the stack so thatRERAISE
can restore it. If an exception occurs, the value stack level and the last instruction on the frame are restored to their current state, and control is transferred to the exception handler attarget
.
- SETUP_WITH(target)¶
Like
SETUP_CLEANUP
, but in case of an exception one more item is popped from the stack before control is transferred to the exception handler attarget
.This variant is used in
with
andasync with
constructs, which push the return value of the context manager's__enter__()
or__aenter__()
to the stack.
- POP_BLOCK¶
Marks the end of the code block associated with the last
SETUP_FINALLY
,SETUP_CLEANUP
orSETUP_WITH
.
- JUMP¶
- JUMP_NO_INTERRUPT¶
Undirected relative jump instructions which are replaced by their directed (forward/backward) counterparts by the assembler.
- LOAD_CLOSURE(i)¶
Pushes a reference to the cell contained in slot
i
of the "fast locals" storage.Note that
LOAD_CLOSURE
is replaced withLOAD_FAST
in the assembler.Modifié dans la version 3.13: This opcode is now a pseudo-instruction.
- LOAD_METHOD¶
Optimized unbound method lookup. Emitted as a
LOAD_ATTR
opcode with a flag set in the arg.
Opcode collections¶
These collections are provided for automatic introspection of bytecode instructions:
Modifié dans la version 3.12: The collections now contain pseudo instructions and instrumented
instructions as well. These are opcodes with values >= MIN_PSEUDO_OPCODE
and >= MIN_INSTRUMENTED_OPCODE
.
- 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.hasarg¶
Sequence of bytecodes that use their argument.
Ajouté dans la version 3.12.
- dis.hasconst¶
Sequence of bytecodes that access a constant.
- dis.hasfree¶
Sequence of bytecodes that access a free (closure) variable. '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.hasjump¶
Sequence of bytecodes that have a jump target. All jumps are relative.
Ajouté dans la version 3.13.
- dis.haslocal¶
Sequence of bytecodes that access a local variable.
- dis.hascompare¶
Sequence of bytecodes of Boolean operations.
- dis.hasexc¶
Sequence of bytecodes that set an exception handler.
Ajouté dans la version 3.12.
- dis.hasjrel¶
Sequence of bytecodes that have a relative jump target.
Obsolète depuis la version 3.13: All jumps are now relative. Use
hasjump
.
- dis.hasjabs¶
Sequence of bytecodes that have an absolute jump target.
Obsolète depuis la version 3.13: All jumps are now relative. This list is empty.