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# numpy.binary_repr

`numpy.``binary_repr`(num, width=None)

  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’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 [R16]. A N-bit two’s-complement 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, the length of the two’s complement if num is negative.
  Returns : | bin : str Binary representation of num or two’s complement of num.

  See also

  `base_repr`
    Return a string representation of a number in the given base system.

  Notes

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

  References

  [R16] | (1, 2) Wikipedia, “Two’s complement”, http://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=4)
      '1101'