`numpy:binary_repr`

source: /dev/numpy/build-install/usr/lib/python3.14/site-packages/numpy/_core/numeric.py :2049

Signature

def binary_repr ( num , width = None )

Summary

Return the binary representation of the input number as a string.

Extended Summary

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's-complement 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 N-bit two's-complement system can represent every integer in the range $- 2^{N - 1}$ to $+ 2^{N - 1} - 1$ .

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, an error is raised.

Returns

bin : str: Binary representation of num or two's complement of num.

Notes

binary_repr is equivalent to using base_repr with base 2, but about 25x faster.

Examples

import numpy as np
np.binary_repr(3)
np.binary_repr(-3)
np.binary_repr(3, width=4)

✓

The two's complement is returned when the input number is negative and width is specified:

np.binary_repr(-3, width=3)
np.binary_repr(-3, width=5)

✓

Aliases

numpy.binary_repr