NDField

This class is used to represent fields of a structured NDArray.

For instance, you can create an array with two fields:

s = blosc2.empty(shape, dtype=[("a", np.float32), ("b", np.float64)])
a = blosc2.NDField(s, "a")
b = blosc2.NDField(s, "b")

class blosc2.NDField(ndarr: NDArray, field: str)

Attributes:

device

Hardware device the array data resides on.

schunk

The associated SChunk.

shape

The shape of the associated NDArray.

Methods

item()	Copy an element of an array to a standard Python scalar and return it.
to_device(device)	Copy the array from the device on which it currently resides to the specified device.
where([value1, value2])	Select value1 or value2 values based on True/False for self.

Special Methods:

__init__(ndarr, field)	Create a new NDField.
__iter__()	Iterate over the elements in the field.
__len__()	Returns the length of the first dimension of the field.
__getitem__(key)	Get a slice of self.
__setitem__(key, value)	Set a slice of self to a value.

Constructor

__init__(ndarr: NDArray, field: str)

Create a new NDField.

Parameters:

• ndarr (NDArray) – The NDArray to which assign the field.

• field (str) – The field’s name.

Returns:

out – The corresponding NDField.

Return type:

NDField

Utility Methods

__iter__()

Iterate over the elements in the field.

Returns:

out

Return type:

iterator

__len__() → int

Returns the length of the first dimension of the field.

__getitem__(key: int | slice | Sequence[slice]) → np.ndarray

Get a slice of self.

Parameters:

key (int or slice or Sequence[slice]) – The slice to be retrieved.

Returns:

out – A NumPy array with the data slice.

Return type:

NumPy.ndarray

__setitem__(key: int | slice | Sequence[slice], value: blosc2.Array) → None

Set a slice of self to a value.

Parameters:

• key (int or slice or Sequence[slice]) – The slice to be set.

• value (blosc2.Array) – The value to be set.

property schunk: SChunk

The associated SChunk.

property shape: tuple[int]

The shape of the associated NDArray.