Jan 12, 2026 · Oct 30, 2025 · Oct 30, 2025 · Oct 30, 2025 · Oct 30, 2025 · Oct 30, 2025
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst

      Return a list of all power-of-two integers contained in a flag.

   :func:`enum.bin`

      Like built-in :func:`bin`, except negative values are represented in
      two's complement, and the leading bit always indicates sign
      (``0`` implies positive, ``1`` implies negative).


 .. versionadded:: 3.6  ``Flag``, ``IntFlag``, ``auto``
 .. versionadded:: 3.11  ``StrEnum``, ``EnumCheck``, ``ReprEnum``, ``FlagBoundary``, ``property``, ``member``, ``nonmember``, ``global_enum``, ``show_flag_values``

   .. versionadded:: 3.11

 .. function:: bin(num, max_bits=None)

   Like built-in :func:`bin`, except negative values are represented in
   two's complement, and the leading bit always indicates sign
   (``0`` implies positive, ``1`` implies negative).

      >>> import enum
      >>> enum.bin(10)
      '0b0 1010'
      >>> enum.bin(~10)   # ~10 is -11
      '0b1 0101'

   .. versionadded:: 3.10

 ---------------

 Notes
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
      >>> f'{14:#b}', f'{14:b}'
      ('0b1110', '1110')

   See also :func:`enum.bin` to represent negative values as twos-complement.

   See also :func:`format` for more information.


diff --git a/Lib/enum.py b/Lib/enum.py
 def bin(num, max_bits=None):
    """
    Like built-in bin(), except negative values are represented in
    twos-compliment, and the leading bit always indicates sign
    twos-complement, and the leading bit always indicates sign
    (0=positive, 1=negative).

    >>> bin(10)
    '0b1 0101'
    """

    num = num.__index__()
    ceiling = 2 ** (num).bit_length()
    if num >= 0:
        s = bltns.bin(num + ceiling).replace('1', '0', 1)
diff --git a/Misc/NEWS.d/next/Documentation/2025-10-30-19-28-42.gh-issue-140806.RBT9YH.rst b/Misc/NEWS.d/next/Documentation/2025-10-30-19-28-42.gh-issue-140806.RBT9YH.rst
 Add documentation for :func:`enum.bin`.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -153,6 +153,12 @@ Module Contents

		Return a list of all power-of-two integers contained in a flag.

		:func:`enum.bin`

		Like built-in :func:`bin`, except negative values are represented in
		two's complement, and the leading bit always indicates sign
		(``0`` implies positive, ``1`` implies negative).


		.. versionadded:: 3.6 ``Flag``, ``IntFlag``, ``auto``
		.. versionadded:: 3.11 ``StrEnum``, ``EnumCheck``, ``ReprEnum``, ``FlagBoundary``, ``property``, ``member``, ``nonmember``, ``global_enum``, ``show_flag_values``
Expand DownExpand Up		@@ -1034,6 +1040,20 @@ Utilities and Decorators

		.. versionadded:: 3.11

		.. function:: bin(num, max_bits=None)

		Like built-in :func:`bin`, except negative values are represented in
		two's complement, and the leading bit always indicates sign
		(``0`` implies positive, ``1`` implies negative).

		>>> import enum
		>>> enum.bin(10)
		'0b0 1010'
		>>> enum.bin(~10) # ~10 is -11
		'0b1 0101'

		.. versionadded:: 3.10

		---------------

		Notes
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -138,6 +138,8 @@ are always available. They are listed here in alphabetical order.
		>>> f'{14:#b}', f'{14:b}'
		('0b1110', '1110')

		See also :func:`enum.bin` to represent negative values as twos-complement.

		See also :func:`format` for more information.


Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -130,7 +130,7 @@ def show_flag_values(value):
		def bin(num, max_bits=None):
		"""
		Like built-in bin(), except negative values are represented in
		twos-compliment, and the leading bit always indicates sign
		twos-complement, and the leading bit always indicates sign
		(0=positive, 1=negative).

		>>> bin(10)
Expand All		@@ -139,6 +139,7 @@ def bin(num, max_bits=None):
		'0b1 0101'
		"""

		num = num.__index__()
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		ceiling = 2 ** (num).bit_length()
		if num >= 0:
		s = bltns.bin(num + ceiling).replace('1', '0', 1)
Expand Down