numpy.binary_repr¶

numpy.
binary_repr
(num, width=None)[源代码]¶ Return the binary representation of the input number as a string.
For negative numbers, if width is not given, a minus sign is added to the front. If width is given, the two’s complement of the number is returned, with respect to that width.
In a two’scomplement system negative numbers are represented by the two’s complement of the absolute value. This is the most common method of representing signed integers on computers [1]. A Nbit two’scomplement system can represent every integer in the range to .
Parameters:  num : int
Only an integer decimal number can be used.
 width : int, optional
The length of the returned string if num is positive, or the length of the two’s complement if num is negative, provided that width is at least a sufficient number of bits for num to be represented in the designated form.
If the width value is insufficient, it will be ignored, and num will be returned in binary (num > 0) or two’s complement (num < 0) form with its width equal to the minimum number of bits needed to represent the number in the designated form. This behavior is deprecated and will later raise an error.
1.12.0 版后已移除.
Returns:  bin : str
Binary representation of num or two’s complement of num.
参见
Notes
binary_repr
is equivalent to usingbase_repr
with base 2, but about 25x faster.References
[1] (1, 2) Wikipedia, “Two’s complement”, https://en.wikipedia.org/wiki/Two’s_complement Examples
>>> np.binary_repr(3) '11' >>> np.binary_repr(3) '11' >>> np.binary_repr(3, width=4) '0011'
The two’s complement is returned when the input number is negative and width is specified:
>>> np.binary_repr(3, width=3) '101' >>> np.binary_repr(3, width=5) '11101'