# sisl.BoundaryCondition

class sisl.BoundaryCondition(value, names=None, *values, module=None, qualname=None, type=None, start=1, boundary=None)[source]

Bases: `IntEnum`

Methods

 `conjugate` Returns self, the complex conjugate of any int. Number of bits necessary to represent self in binary. Number of ones in the binary representation of the absolute value of self. `to_bytes`([length, byteorder, signed]) Return an array of bytes representing an integer. `from_bytes`([byteorder, signed]) Return the integer represented by the given array of bytes. Return a pair of integers, whose ratio is equal to the original int. Returns True. `getitem`(key) Search for a specific integer entry by value, and not by name `real` the real part of a complex number `imag` the imaginary part of a complex number `numerator` the numerator of a rational number in lowest terms `denominator` the denominator of a rational number in lowest terms `UNKNOWN` `PERIODIC` `DIRICHLET` `NEUMANN` `OPEN`
DIRICHLET = 3
NEUMANN = 4
OPEN = 5
PERIODIC = 2
UNKNOWN = 1
__init__(*args, **kwds)
as_integer_ratio()

Return a pair of integers, whose ratio is equal to the original int.

The ratio is in lowest terms and has a positive denominator.

```>>> (10).as_integer_ratio()
(10, 1)
>>> (-10).as_integer_ratio()
(-10, 1)
>>> (0).as_integer_ratio()
(0, 1)
```
bit_count()

Number of ones in the binary representation of the absolute value of self.

Also known as the population count.

```>>> bin(13)
'0b1101'
>>> (13).bit_count()
3
```
bit_length()

Number of bits necessary to represent self in binary.

```>>> bin(37)
'0b100101'
>>> (37).bit_length()
6
```
conjugate()

Returns self, the complex conjugate of any int.

denominator

the denominator of a rational number in lowest terms

from_bytes(byteorder='big', *, signed=False)

Return the integer represented by the given array of bytes.

bytes

Holds the array of bytes to convert. The argument must either support the buffer protocol or be an iterable object producing bytes. Bytes and bytearray are examples of built-in objects that support the buffer protocol.

byteorder

The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.

signed

Indicates whether two’s complement is used to represent the integer.

classmethod getitem(key)[source]

Search for a specific integer entry by value, and not by name

imag

the imaginary part of a complex number

is_integer()

Returns True. Exists for duck type compatibility with float.is_integer.

numerator

the numerator of a rational number in lowest terms

real

the real part of a complex number

to_bytes(length=1, byteorder='big', *, signed=False)

Return an array of bytes representing an integer.

length

Length of bytes object to use. An OverflowError is raised if the integer is not representable with the given number of bytes. Default is length 1.

byteorder

The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.

signed

Determines whether two’s complement is used to represent the integer. If signed is False and a negative integer is given, an OverflowError is raised.