# `dis` --- Disassembler for Python bytecode

ソースコード: Lib/dis.py

`dis` モジュールは CPython バイトコード を逆アセンブルすることでバイトコードの解析をサポートします。このモジュールが入力として受け取る CPython バイトコードはファイル `Include/opcode.h` に定義されており、 コンパイラとインタプリタが使用しています。

CPython 実装の詳細: バイトコードは CPython インタプリタの実装詳細です。Python のバージョン間でバイトコードの追加や、削除、変更がないという保証はありません。このモジュールを使用することによって Python の異なる VM または異なるリリースの間で動作すると考えるべきではありません。

バージョン 3.6 で変更: 従来は使用されるバイト数は命令ごとに異なりましたが、このモジュールでは各々一つの命令につき2バイト使用することとなっています。

バージョン 3.10 で変更: The argument of jump, exception handling and loop instructions is now the instruction offset rather than the byte offset.

バージョン 3.11 で変更: 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`.

バージョン 3.12 で変更: 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.

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 RESUME                   0

      3           2 LOAD_GLOBAL              1 (NULL + len)
                 12 LOAD_FAST                0 (alist)
                 14 CALL                     1
                 22 RETURN_VALUE

("2" は行番号です)。

## コマンドライン・インターフェース

The `dis` module can be invoked as a script from the command line:

    python -m dis [-h] [infile]

以下のオプションが使用できます:

-h, --help

  使い方を表示して終了します。

If `infile` is specified, its disassembled code will be written to stdout. Otherwise, disassembly is performed on compiled source code recieved from stdin.

## バイトコード解析

Added in version 3.4.

バイトコード解析の API を使うと、 Python のコード片を `Bytecode` オブジェクトでラップでき、コンパイルされたコードの細かいところに簡単にアクセスできます。

class dis.Bytecode(x, *, first_line=None, current_offset=None, show_caches=False, adaptive=False)

  関数、ジェネレータ、非同期ジェネレータ、コルーチン、メソッド、ソースコード文字列、(`compile()` が返すような) コードオブジェクトに対応するバイトコードを解析します。

  これは、下で並べられている関数の多くのものをまとめた便利なラッパーです。 とりわけ目立つのは `get_instructions()` で、 `Bytecode` インスタンスに対し反復処理をしながら、バイトコード命令を `Instruction` インスタンスとして返します。

  first_line が `None` でない場合は、それを逆アセンブルしたコードのソースの最初の行に表示する行番号とします。 そうでない場合は、ソースの行の情報 (もしあれば) を逆アセンブルされたコードオブジェクトから直接取得します。

  current_offset が `None` でない場合は、逆アセンブルされたコードでのあるインストラクションのオフセット位置を示します。 これを設定すると、 `dis()` の出力において、指定された命令コード (opcode) に "現在の命令 (instruction)" を表す印が表示されます。

  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.

  classmethod from_traceback(tb, *, show_caches=False)

    与えられたトレースバックから `Bytecode` インスタンスを構築し、 current_offset がその例外の原因となった命令となるよう設定します。

  codeobj

    コンパイルされたコードオブジェクト。

  first_line

    コードオブジェクトのソースの最初の行 (利用可能であれば)

  dis()

    バイトコード命令の整形された表示を返します (`dis.dis()` と同じ出力になりますが、複数行文字列として返されます)。

  info()

    `code_info()` のようなコードオブジェクトの詳細を含んだ整形された複数行文字列を返します。

  バージョン 3.7 で変更: This can now handle coroutine and asynchronous generator objects.

  バージョン 3.11 で変更: Added the show_caches and adaptive parameters.

例:

    >>> bytecode = dis.Bytecode(myfunc)
    >>> for instr in bytecode:
    ...     print(instr.opname)
    ...
    RESUME
    LOAD_GLOBAL
    LOAD_FAST
    CALL
    RETURN_VALUE

## 解析関数

`dis` モジュールには、以下に挙げる入力を直接欲しい出力に変換する解析関数も定義してあります。 1つの命令だけが実行されている場合は、解析オブジェクトをいったん作るよりはこちらの方が便利です:

dis.code_info(x)

  渡された関数、ジェネレータ、非同期ジェネレータ、コルーチン、メソッド、ソースコード文字列、コードオブジェクトに対する、詳細なコードオブジェクトの情報を、整形された複数行の文字列として返します。

  この結果は実装に強く依存しており、Python VM や Python のバージョンによって異なることがあります。

  Added in version 3.2.

  バージョン 3.7 で変更: This can now handle coroutine and asynchronous generator objects.

dis.show_code(x, *, file=None)

  渡された関数、メソッド、ソースコード文字列、コードオブジェクトに対する、詳細なコードオブジェクトの情報を、file (または file が指定されていなければ `sys.stdout`) に表示します。

  これは、インタラクティブシェル上で使うことを想定した、`print(code_info(x), file=file)` の便利なショートカットです。

  Added in version 3.2.

  バージョン 3.4 で変更: file 引数が追加されました。

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.

  file 引数が渡された場合は、アセンブリをそこに書き込みます。 そうでない場合は `sys.stdout` に出力します。

  The maximal depth of recursion is limited by depth unless it is `None`. `depth=0` means no recursion.

  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.

  バージョン 3.4 で変更: file 引数が追加されました。

  バージョン 3.7 で変更: Implemented recursive disassembling and added depth parameter.

  バージョン 3.7 で変更: This can now handle coroutine and asynchronous generator objects.

  バージョン 3.11 で変更: Added the show_caches and adaptive parameters.

dis.distb(tb=None, *, file=None, show_caches=False, adaptive=False)

  トレースバックのスタックの先頭の関数を逆アセンブルします。Noneが渡された場合は最後のトレースバックを使います。例外を引き起こした命令が表示されます。

  file 引数が渡された場合は、アセンブリをそこに書き込みます。 そうでない場合は `sys.stdout` に出力します。

  バージョン 3.4 で変更: file 引数が追加されました。

  バージョン 3.11 で変更: Added the show_caches and adaptive parameters.

dis.disassemble(code, lasti=-1, *, file=None, show_caches=False, adaptive=False)
dis.disco(code, lasti=-1, *, file=None, show_caches=False, adaptive=False)

  コードオブジェクトを逆アセンブルします。lasti が与えられた場合は、最後の命令を示します。出力は次のようなカラムに分割されます:

  1. 各行の最初の命令に対する行番号。

  2. 現在の命令。 `-->` として示されます。

  3. ラベル付けされた命令。 `>>` とともに表示されます。

  4. 命令のアドレス。

  5. 命令コード名。

  6. 命令パラメタ。

  7. パラメタの解釈を括弧で囲んだもの。

  パラメタの解釈は、ローカル変数とグローバル変数の名前、定数の値、 分岐先、比較命令を認識します。

  file 引数が渡された場合は、アセンブリをそこに書き込みます。 そうでない場合は `sys.stdout` に出力します。

  バージョン 3.4 で変更: file 引数が追加されました。

  バージョン 3.11 で変更: Added the show_caches and adaptive parameters.

dis.get_instructions(x, *, first_line=None, show_caches=False, adaptive=False)

  渡された関数、メソッド、ソースコード文字列、コードオブジェクトにある命令のイテレータを返します。

  イテレータは、与えられたコードの各命令の詳細情報を保持する名前付きタプル `Instruction` からなる列を生成します。

  first_line が `None` でない場合は、それを逆アセンブルしたコードのソースの最初の行に表示する行番号とします。 そうでない場合は、ソースの行の情報 (もしあれば) を逆アセンブルされたコードオブジェクトから直接取得します。

  The show_caches and adaptive parameters work as they do in `dis()`.

  Added in version 3.4.

  バージョン 3.11 で変更: Added the show_caches and adaptive parameters.

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.

  バージョン 3.6 で変更: Line numbers can be decreasing. Before, they were always increasing.

  バージョン 3.10 で変更: The PEP 626 `co_lines()` method is used instead of the `co_firstlineno` and `co_lnotab` attributes of the code object.

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)

  opcode と引数 oparg がスタックに与える影響を計算します。

  If the code has a jump target and jump is `True`, `stack_effect()` will return the stack effect of jumping. If jump is `False`, it will return the stack effect of not jumping. And if jump is `None` (default), it will return the maximal stack effect of both cases.

  Added in version 3.4.

  バージョン 3.8 で変更: Added jump parameter.

## Python バイトコード命令

`get_instructions()` 関数と `Bytecode` クラスはバイトコード命令の詳細を `Instruction` インスタンスの形で提供します:

class dis.Instruction

  バイトコード命令の詳細

  opcode

    以下の命令コードの値と 命令コードコレクション のバイトコードの値に対応する、命令の数値コードです。

  opname

    人間が読むための命令名

  arg

    (ある場合は) 命令の数値引数、無ければ `None`

  argval

    resolved arg value (if any), otherwise `None`

  argrepr

    human readable description of operation argument (if any), otherwise an empty string.

  offset

    バイトコード列の中での命令の開始位置

  starts_line

    line started by this opcode (if any), otherwise `None`

  is_jump_target

    他のコードからここへジャンプする場合は `True` 、そうでない場合は `False`

  positions

    `dis.Positions` object holding the start and end locations that are covered by this instruction.

  Added in version 3.4.

  バージョン 3.11 で変更: Field `positions` is added.

class dis.Positions

  In case the information is not available, some fields might be `None`.

  lineno
  end_lineno
  col_offset
  end_col_offset

  Added in version 3.11.

現在 Python コンパイラは次のバイトコード命令を生成します。

一般的な命令

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 two values from the stack. Equivalent to `POP_TOP`; `POP_TOP`. Used to clean up at the end of loops, hence the name.

  Added in version 3.12.

END_SEND

  Implements `del STACK[-2]`. Used to clean up when a generator exits.

  Added in 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])

  Added in version 3.11.

SWAP(i)

  Swap the top of the stack with the i-th element:

      STACK[-i], STACK[-1] = STACK[-1], STACK[-i]

  Added in 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 with `show_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.

  Added in version 3.11.

1オペランド命令

1オペランド命令はスタックの先頭を取り出して操作を適用し、結果をスタックへプッシュし戻します。

UNARY_NEGATIVE

  Implements `STACK[-1] = -STACK[-1]`.

UNARY_NOT

  Implements `STACK[-1] = not STACK[-1]`.

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, implements `STACK[-1] = iter(STACK[-1])`.

  Added in version 3.5.

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)

  Added in 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])

  Added in version 3.12.

STORE_SLICE

  Implements:

      end = STACK.pop()
      start = STACK.pop()
      container = STACK.pop()
      values = STACK.pop()
      container[start:end] = value

  Added in version 3.12.

コルーチン命令コード

GET_AWAITABLE(where)

  Implements `STACK[-1] = get_awaitable(STACK[-1])`, where `get_awaitable(o)` returns `o` if `o` is a coroutine object or a generator object with the `CO_ITERABLE_COROUTINE` flag, or resolves `o.__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__`

  Added in version 3.5.

  バージョン 3.11 で変更: Previously, this instruction did not have an oparg.

GET_AITER

  Implements `STACK[-1] = STACK[-1].__aiter__()`.

  Added in version 3.5.

  バージョン 3.7 で変更: Returning awaitable objects from `__aiter__` is no longer supported.

GET_ANEXT

  Implement `STACK.append(get_awaitable(STACK[-1].__anext__()))` to the stack. See `GET_AWAITABLE` for details about `get_awaitable`.

  Added in 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 in `STACK[-2]` and the raised exception in `STACK[-1]`. Both are popped. If the exception is not `StopAsyncIteration`, it is re-raised.

  Added in version 3.8.

  バージョン 3.11 で変更: Exception representation on the stack now consist of one, not three, items.

CLEANUP_THROW

  Handles an exception raised during a `throw()` or `close()` call through the current frame. If `STACK[-1]` is an instance of `StopIteration`, pop three values from the stack and push its `value` member. Otherwise, re-raise `STACK[-1]`.

  Added in version 3.12.

BEFORE_ASYNC_WITH

  Resolves `__aenter__` and `__aexit__` from `STACK[-1]`. Pushes `__aexit__` and result of `__aenter__()` to the stack:

      STACK.extend((__aexit__, __aenter__())

  Added in version 3.5.

その他の命令コード

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.

  Added in version 3.1.

  バージョン 3.8 で変更: Map value is `STACK[-1]` and map key is `STACK[-2]`. Before, those were reversed.

`SET_ADD`, `LIST_APPEND`, `MAP_ADD` は、追加した値または key/value ペアをスタックから取り除きますが、コンテナオブジェクトはループの次のイテレーションで利用できるようにスタックに残しておきます。

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.

  Added in version 3.12.

YIELD_VALUE

  Yields `STACK.pop()` from a generator.

  バージョン 3.11 で変更: oparg set to be the stack depth.

  バージョン 3.12 で変更: oparg set to be the exception block depth, for efficient closing of generators.

SETUP_ANNOTATIONS

  Checks whether `__annotations__` is defined in `locals()`, if not it is set up to an empty `dict`. This opcode is only emitted if a class or module body contains variable annotations statically.

  Added in version 3.6.

POP_EXCEPT

  Pops a value from the stack, which is used to restore the exception state.

  バージョン 3.11 で変更: 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.

  Added in version 3.9.

  バージョン 3.11 で変更: 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.

  Added in version 3.11.

CHECK_EXC_MATCH

  Performs exception matching for `except`. Tests whether the `STACK[-2]` is an exception matching `STACK[-1]`. Pops `STACK[-1]` and pushes the boolean result of the test.

  Added in version 3.11.

CHECK_EG_MATCH

  Performs exception matching for `except*`. Applies `split(STACK[-1])` on the exception group representing `STACK[-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 pushes `None`.

  Added in 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 a `with` statement.

  Added in version 3.9.

  バージョン 3.11 で変更: 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 the `assert` statement.

  Added in 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 by `WITH_EXCEPT_START`. Then, `__enter__()` is called. Finally, the result of calling the `__enter__()` method is pushed onto the stack.

  Added in version 3.11.

GET_LEN

  Perform `STACK.append(len(STACK[-1]))`.

  Added in version 3.10.

MATCH_MAPPING

  If `STACK[-1]` is an instance of `collections.abc.Mapping` (or, more technically: if it has the `Py_TPFLAGS_MAPPING` flag set in its `tp_flags`), push `True` onto the stack. Otherwise, push `False`.

  Added in version 3.10.

MATCH_SEQUENCE

  If `STACK[-1]` is an instance of `collections.abc.Sequence` and is not an instance of `str`/`bytes`/`bytearray` (or, more technically: if it has the `Py_TPFLAGS_SEQUENCE` flag set in its `tp_flags`), push `True` onto the stack. Otherwise, push `False`.

  Added in version 3.10.

MATCH_KEYS

  `STACK[-1]` is a tuple of mapping keys, and `STACK[-2]` is the match subject. If `STACK[-2]` contains all of the keys in `STACK[-1]`, push a `tuple` containing the corresponding values. Otherwise, push `None`.

  Added in version 3.10.

  バージョン 3.11 で変更: 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 attribute `co_names` of the code object. The compiler tries to use `STORE_FAST` or `STORE_GLOBAL` if possible.

DELETE_NAME(namei)

  Implements `del name`, where namei is the index into `co_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 as `STACK.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)

  `STORE_NAME` と同じように動作しますが、 name をグローバルとして保存します。

DELETE_GLOBAL(namei)

  `DELETE_NAME` と同じように動作しますが、グローバルの name を削除します。

LOAD_CONST(consti)

  `co_consts[consti]` をスタックにプッシュします。

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` and `LOAD_FROM_DICT_OR_GLOBALS`.

  Added in 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 to `LOAD_GLOBAL`. This is used for loading global variables in annotation scopes within class bodies.

  Added in version 3.12.

BUILD_TUPLE(count)

  Creates a tuple consuming count items from the stack, and pushes the resulting tuple onto the stack.:

      assert count > 0
      STACK, values = STACK[:-count], STACK[-count:]
      STACK.append(tuple(values))

BUILD_LIST(count)

  `BUILD_TUPLE` と同じように動作しますが、この命令はリストを作り出します。

BUILD_SET(count)

  `BUILD_TUPLE` と同じように動作しますが、この命令は set を作り出します。

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]}`.

  バージョン 3.5 で変更: 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 from `STACK[-2]`, pops count values to form values in the built dictionary.

  Added in version 3.6.

BUILD_STRING(count)

  Concatenates count strings from the stack and pushes the resulting string onto the stack.

  Added in version 3.6.

LIST_EXTEND(i)

  Implements:

      seq = STACK.pop()
      list.extend(STACK[-i], seq)

  Used to build lists.

  Added in version 3.9.

SET_UPDATE(i)

  Implements:

      seq = STACK.pop()
      set.update(STACK[-i], seq)

  Used to build sets.

  Added in version 3.9.

DICT_UPDATE(i)

  Implements:

      map = STACK.pop()
      dict.update(STACK[-i], map)

  Used to build dicts.

  Added in version 3.9.

DICT_MERGE(i)

  Like `DICT_UPDATE` but raises an exception for duplicate keys.

  Added in version 3.9.

LOAD_ATTR(namei)

  If the low bit of `namei` is not set, this replaces `STACK[-1]` with `getattr(STACK[-1], co_names[namei>>1])`.

  If the low bit of `namei` is set, this will attempt to load a method named `co_names[namei>>1]` from the `STACK[-1]` object. `STACK[-1]` is popped. This bytecode distinguishes two cases: if `STACK[-1]` has a method with the correct name, the bytecode pushes the unbound method and `STACK[-1]`. `STACK[-1]` will be used as the first argument (`self`) by `CALL` when calling the unbound method. Otherwise, `NULL` and the object returned by the attribute lookup are pushed.

  バージョン 3.12 で変更: If the low bit of `namei` is set, then a `NULL` or `self` 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` and `super(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 method - `cls`: the class within which the current method was defined - the global `super`

  With respect to its argument, it works similarly to `LOAD_ATTR`, except that `namei` is shifted left by 2 bits instead of 1.

  The low bit of `namei` signals to attempt a method load, as with `LOAD_ATTR`, which results in pushing `NULL` 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 to `super()` (unset means zero-argument).

  Added in version 3.12.

COMPARE_OP(opname)

  Performs a Boolean operation. The operation name can be found in `cmp_op[opname]`.

IS_OP(invert)

  Performs `is` comparison, or `is not` if `invert` is 1.

  Added in version 3.9.

CONTAINS_OP(invert)

  Performs `in` comparison, or `not in` if `invert` is 1.

  Added in version 3.9.

IMPORT_NAME(namei)

  Imports the module `co_names[namei]`. `STACK[-1]` and `STACK[-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 subsequent `STORE_FAST` instruction modifies the namespace.

IMPORT_FROM(namei)

  Loads the attribute `co_names[namei]` from the module found in `STACK[-1]`. The resulting object is pushed onto the stack, to be subsequently stored by a `STORE_FAST` instruction.

JUMP_FORWARD(delta)

  バイトコードカウンタを delta だけ増加させます。

JUMP_BACKWARD(delta)

  Decrements bytecode counter by delta. Checks for interrupts.

  Added in version 3.11.

JUMP_BACKWARD_NO_INTERRUPT(delta)

  Decrements bytecode counter by delta. Does not check for interrupts.

  Added in version 3.11.

POP_JUMP_IF_TRUE(delta)

  If `STACK[-1]` is true, increments the bytecode counter by delta. `STACK[-1]` is popped.

  バージョン 3.11 で変更: 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).

  バージョン 3.12 で変更: This is no longer a pseudo-instruction.

POP_JUMP_IF_FALSE(delta)

  If `STACK[-1]` is false, increments the bytecode counter by delta. `STACK[-1]` is popped.

  バージョン 3.11 で変更: 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).

  バージョン 3.12 で変更: This is no longer a pseudo-instruction.

POP_JUMP_IF_NOT_NONE(delta)

  If `STACK[-1]` is not `None`, 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).

  Added in version 3.11.

  バージョン 3.12 で変更: This is no longer a pseudo-instruction.

POP_JUMP_IF_NONE(delta)

  If `STACK[-1]` is `None`, 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).

  Added in version 3.11.

  バージョン 3.12 で変更: 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.

  バージョン 3.12 で変更: Up until 3.11 the iterator was popped when it was exhausted.

LOAD_GLOBAL(namei)

  `co_names[namei>>1]` という名前のグローバルをスタック上にロードします。

  バージョン 3.11 で変更: If the low bit of `namei` is set, then a `NULL` is pushed to the stack before the global variable.

LOAD_FAST(var_num)

  ローカルな `co_varnames[var_num]` への参照をスタックにプッシュします。

  バージョン 3.12 で変更: 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 an `UnboundLocalError` if the local variable has not been initialized.

  Added in version 3.12.

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`.

  Added in version 3.12.

STORE_FAST(var_num)

  Stores `STACK.pop()` into the local `co_varnames[var_num]`.

DELETE_FAST(var_num)

  ローカルな `co_varnames[var_num]` を削除します。

MAKE_CELL(i)

  Creates a new cell in slot `i`. If that slot is nonempty then that value is stored into the new cell.

  Added in version 3.11.

LOAD_CLOSURE(i)

  Pushes a reference to the cell contained in slot `i` of the "fast locals" storage. The name of the variable is `co_fastlocalnames[i]`.

  Note that `LOAD_CLOSURE` is effectively an alias for `LOAD_FAST`. It exists to keep bytecode a little more readable.

  バージョン 3.11 で変更: `i` is no longer offset by the length of `co_varnames`.

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.

  バージョン 3.11 で変更: `i` is no longer offset by the length of `co_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 slot `i`, similar to `LOAD_DEREF`. This is used for loading free variables in class bodies (which previously used `LOAD_CLASSDEREF`) and in annotation scopes within class bodies.

  Added in version 3.12.

STORE_DEREF(i)

  Stores `STACK.pop()` into the cell contained in slot `i` of the "fast locals" storage.

  バージョン 3.11 で変更: `i` is no longer offset by the length of `co_varnames`.

DELETE_DEREF(i)

  Empties the cell contained in slot `i` of the "fast locals" storage. Used by the `del` statement.

  Added in version 3.2.

  バージョン 3.11 で変更: `i` is no longer offset by the length of `co_varnames`.

COPY_FREE_VARS(n)

  Copies the `n` free variables from the closure into the frame. Removes the need for special code on the caller's side when calling closures.

  Added in 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 at `STACK[-1]`)

  - 2: `raise STACK[-2] from STACK[-1]` (raise exception instance or type at `STACK[-2]` with `__cause__` set to `STACK[-1]`)

CALL(argc)

  Calls a callable object with the number of arguments specified by `argc`, including the named arguments specified by the preceding `KW_NAMES`, if any. On the stack are (in ascending order), either:

  - NULL

  - The callable

  - The positional arguments

  - The named arguments

  or:

  - The callable

  - `self`

  - The remaining positional arguments

  - The named arguments

  `argc` is the total of the positional and named arguments, excluding `self` when a `NULL` is not present.

  `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.

  Added in version 3.11.

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.

  Added in version 3.6.

PUSH_NULL

  Pushes a `NULL` to the stack. Used in the call sequence to match the `NULL` pushed by `LOAD_METHOD` for non-method calls.

  Added in version 3.11.

KW_NAMES(consti)

  Prefixes `CALL`. Stores a reference to `co_consts[consti]` into an internal variable for use by `CALL`. `co_consts[consti]` must be a tuple of strings.

  Added in version 3.11.

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 order

  - `0x02` a dictionary of keyword-only parameters' default values

  - `0x04` a tuple of strings containing parameters' annotations

  - `0x08` a tuple containing cells for free variables, making a closure

  - the code associated with the function (at `STACK[-1]`)

  バージョン 3.10 で変更: Flag value `0x04` is a tuple of strings instead of dictionary

  バージョン 3.11 で変更: Qualified name at `STACK[-1]` was removed.

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, stop))

  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.

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`: call `str()` on value before formatting it.

  - `(flags & 0x03) == 0x02`: call `repr()` on value before formatting it.

  - `(flags & 0x03) == 0x03`: call `ascii()` 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.

  Added in version 3.6.

MATCH_CLASS(count)

  `STACK[-1]` is a tuple of keyword attribute names, `STACK[-2]` is the class being matched against, and `STACK[-3]` is the match subject. count is the number of positional sub-patterns.

  Pop `STACK[-1]`, `STACK[-2]`, and `STACK[-3]`. If `STACK[-3]` is an instance of `STACK[-2]` and has the positional and keyword attributes required by count and `STACK[-1]`, push a tuple of extracted attributes. Otherwise, push `None`.

  Added in version 3.10.

  バージョン 3.11 で変更: Previously, this instruction also pushed a boolean value indicating success (`True`) or failure (`False`).

RESUME(where)

  A no-op. Performs internal tracing, debugging and optimization checks.

  The `where` operand marks where the `RESUME` occurs:

  - `0` The start of a function, which is neither a generator, coroutine nor an async generator

  - `1` After a `yield` expression

  - `2` After a `yield from` expression

  - `3` After an `await` expression

  Added in version 3.11.

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.

  Added in version 3.11.

SEND(delta)

  Equivalent to `STACK[-1] = STACK[-2].send(STACK[-1])`. Used in `yield from` and `await` statements.

  If the call raises `StopIteration`, pop the top value from the stack, push the exception's `value` attribute, and increment the bytecode counter by delta.

  Added in 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, use the `hasarg` collection instead.

  バージョン 3.6 で変更: Now every instruction has an argument, but opcodes `< HAVE_ARGUMENT` ignore it. Before, only opcodes `>= HAVE_ARGUMENT` had an argument.

  バージョン 3.12 で変更: Pseudo instructions were added to the `dis` module, and for them it is not true that comparison with `HAVE_ARGUMENT` indicates whether they use their arg.

CALL_INTRINSIC_1

  Calls an intrinsic function with one argument. Passes `STACK[-1]` as the argument and sets `STACK[-1]` to the result. Used to implement functionality that is not performance critical.

  The operand determines which intrinsic function is called:

  Operand | 説明
  --- | ---
  `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 aync generator value
  `INTRINSIC_UNARY_POSITIVE` | Performs the unary `+` operation
  `INTRINSIC_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 argument
  `INTRINSIC_TYPEALIAS` | Creates a `typing.TypeAliasType`; used in the `type` statement. The argument is a tuple of the type alias's name, type parameters, and value.

  Added in 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.push(result)

  The operand determines which intrinsic function is called:

  Operand | 説明
  --- | ---
  `INTRINSIC_2_INVALID` | Not valid
  `INTRINSIC_PREP_RERAISE_STAR` | Calculates the `ExceptionGroup` to raise from a `try-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.

  Added in 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 that `RERAISE` 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 at `target`.

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 at `target`.

  This variant is used in `with` and `async 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` or `SETUP_WITH`.

JUMP

JUMP_NO_INTERRUPT

  Undirected relative jump instructions which are replaced by their directed (forward/backward) counterparts by the assembler.

LOAD_METHOD

  Optimized unbound method lookup. Emitted as a `LOAD_ATTR` opcode with a flag set in the arg.

## 命令コードコレクション

これらのコレクションは、自動でバイトコード命令を解析するために提供されています:

バージョン 3.12 で変更: 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

  命令コード名のリスト。 バイトコードをインデックスに使って参照できます。

dis.opmap

  命令コード名をバイトコードに対応づける辞書。

dis.cmp_op

  すべての比較命令の名前のリスト。

dis.hasarg

  Sequence of bytecodes that use their argument.

  Added in version 3.12.

dis.hasconst

  定数にアクセスするバイトコードのリスト。

dis.hasfree

  Sequence of bytecodes that access a free 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

  名前によって属性にアクセスするバイトコードのリスト。

dis.hasjrel

  相対ジャンプ先を持つバイトコードのリスト。

dis.hasjabs

  絶対ジャンプ先を持つバイトコードのリスト。

dis.haslocal

  ローカル変数にアクセスするバイトコードのリスト。

dis.hascompare

  ブール命令のバイトコードのリスト。

dis.hasexc

  Sequence of bytecodes that set an exception handler.

  Added in version 3.12.