zarr.create

zarr.create

create(
    shape: tuple[int, ...] | int,
    *,
    chunks: tuple[int, ...] | int | bool | None = None,
    dtype: ZDTypeLike | None = None,
    compressor: CompressorLike = "auto",
    fill_value: Any | None = DEFAULT_FILL_VALUE,
    order: MemoryOrder | None = None,
    store: StoreLike | None = None,
    synchronizer: Any | None = None,
    overwrite: bool = False,
    path: PathLike | None = None,
    chunk_store: StoreLike | None = None,
    filters: Iterable[dict[str, JSON] | Numcodec]
    | None = None,
    cache_metadata: bool | None = None,
    cache_attrs: bool | None = None,
    read_only: bool | None = None,
    object_codec: Codec | None = None,
    dimension_separator: Literal[".", "/"] | None = None,
    write_empty_chunks: bool | None = None,
    zarr_format: ZarrFormat | None = None,
    meta_array: Any | None = None,
    attributes: dict[str, JSON] | None = None,
    chunk_shape: tuple[int, ...] | int | None = None,
    chunk_key_encoding: ChunkKeyEncoding
    | tuple[Literal["default"], Literal[".", "/"]]
    | tuple[Literal["v2"], Literal[".", "/"]]
    | None = None,
    codecs: Iterable[Codec | dict[str, JSON]] | None = None,
    dimension_names: DimensionNamesLike = None,
    storage_options: dict[str, Any] | None = None,
    config: ArrayConfigLike | None = None,
    **kwargs: Any,
) -> AnyArray

Create an array.

Parameters:

• shape (int or tuple of ints) –

  Array shape.

• chunks (int or tuple of ints, default: None ) –

  Chunk shape. If True, will be guessed from shape and dtype. If False, will be set to shape, i.e., single chunk for the whole array. If an int, the chunk size in each dimension will be given by the value of chunks. Default is True.

• dtype (str or dtype, default: None ) –

  NumPy dtype.

• compressor (Codec, default: 'auto' ) –

  Primary compressor to compress chunk data. Zarr format 2 only. Zarr format 3 arrays should use codecs instead.

  If neither compressor nor filters are provided, the default compressor zarr.codecs.ZstdCodec is used.

  If compressor is set to None, no compression is used.

• fill_value (Any, default: DEFAULT_FILL_VALUE ) –

  Fill value for the array.

• order (('C', 'F'), default: 'C' ) –

  Deprecated in favor of the config keyword argument. Pass {'order': <value>} to create instead of using this parameter. Memory layout to be used within each chunk. If not specified, the array.order parameter in the global config will be used.

• store (StoreLike or None, default: None ) –

  StoreLike object to open. See the storage documentation in the user guide for a description of all valid StoreLike values.

• synchronizer (object, default: None ) –

  Array synchronizer.

• overwrite (bool, default: False ) –

  If True, delete all pre-existing data in store at path before creating the array.

• path (str, default: None ) –

  Path under which array is stored.

• chunk_store (StoreLike or None, default: None ) –

  Separate storage for chunks. If not provided, store will be used for storage of both chunks and metadata.

• filters (Iterable[Codec] | Literal['auto'], default: None ) –

  Iterable of filters to apply to each chunk of the array, in order, before serializing that chunk to bytes.

  For Zarr format 3, a "filter" is a codec that takes an array and returns an array, and these values must be instances of zarr.abc.codec.ArrayArrayCodec, or a dict representations of zarr.abc.codec.ArrayArrayCodec.

  For Zarr format 2, a "filter" can be any numcodecs codec; you should ensure that the order of your filters is consistent with the behavior of each filter.

  The default value of "auto" instructs Zarr to use a default based on the data type of the array and the Zarr format specified. For all data types in Zarr V3, and most data types in Zarr V2, the default filters are empty. The only cases where default filters are not empty is when the Zarr format is 2, and the data type is a variable-length data type like zarr.dtype.VariableLengthUTF8 or zarr.dtype.VariableLengthUTF8. In these cases, the default filters contains a single element which is a codec specific to that particular data type.

  To create an array with no filters, provide an empty iterable or the value None.

• cache_metadata (bool, default: None ) –

  If True, array configuration metadata will be cached for the lifetime of the object. If False, array metadata will be reloaded prior to all data access and modification operations (may incur overhead depending on storage and data access pattern).

• cache_attrs (bool, default: None ) –

  If True (default), user attributes will be cached for attribute read operations. If False, user attributes are reloaded from the store prior to all attribute read operations.

• read_only (bool, default: None ) –

  True if array should be protected against modification.

• object_codec (Codec, default: None ) –

  A codec to encode object arrays, only needed if dtype=object.

• dimension_separator (('.', '/'), default: '.' ) –

  Separator placed between the dimensions of a chunk. Zarr format 2 only. Zarr format 3 arrays should use chunk_key_encoding instead.

• write_empty_chunks (bool, default: None ) –

  Deprecated in favor of the config keyword argument. Pass {'write_empty_chunks': <value>} to create instead of using this parameter. If True, all chunks will be stored regardless of their contents. If False, each chunk is compared to the array's fill value prior to storing. If a chunk is uniformly equal to the fill value, then that chunk is not be stored, and the store entry for that chunk's key is deleted.

• zarr_format ((2, 3, None), default: 2 ) –

  The Zarr format to use when creating an array. The default is None, which instructs Zarr to choose the default Zarr format value defined in the runtime configuration.

• meta_array (array - like, default: None ) –

  Not implemented.

• attributes (dict[str, JSON], default: None ) –

  A dictionary of user attributes to store with the array.

• chunk_shape (int or tuple of ints, default: None ) –

  The shape of the Array's chunks (default is None). Zarr format 3 only. Zarr format 2 arrays should use chunks instead.

• chunk_key_encoding (ChunkKeyEncoding, default: None ) –

  A specification of how the chunk keys are represented in storage. Zarr format 3 only. Zarr format 2 arrays should use dimension_separator instead. Default is ("default", "/").

• codecs (Sequence of Codecs or dicts, default: None ) –

  An iterable of Codec or dict serializations of Codecs. Zarr V3 only.

  The elements of codecs specify the transformation from array values to stored bytes. Zarr format 3 only. Zarr format 2 arrays should use filters and compressor instead.

  If no codecs are provided, default codecs will be used based on the data type of the array. For most data types, the default codecs are the tuple (BytesCodec(), ZstdCodec()); data types that require a special zarr.abc.codec.ArrayBytesCodec, like variable-length strings or bytes, will use the zarr.abc.codec.ArrayBytesCodec required for the data type instead of zarr.codecs.BytesCodec.

• dimension_names (Iterable[str | None] | None = None, default: None ) –

  An iterable of dimension names. Zarr format 3 only.

• storage_options (dict, default: None ) –

  If using an fsspec URL to create the store, these will be passed to the backend implementation. Ignored otherwise.

• config (ArrayConfigLike, default: None ) –

  Runtime configuration of the array. If provided, will override the default values from zarr.config.array.

Returns:

• z ( Array ) –

  The array.

Source code in zarr/api/synchronous.py

def create(
    shape: tuple[int, ...] | int,
    *,  # Note: this is a change from v2
    chunks: tuple[int, ...] | int | bool | None = None,
    dtype: ZDTypeLike | None = None,
    compressor: CompressorLike = "auto",
    fill_value: Any | None = DEFAULT_FILL_VALUE,  # TODO: need type
    order: MemoryOrder | None = None,
    store: StoreLike | None = None,
    synchronizer: Any | None = None,
    overwrite: bool = False,
    path: PathLike | None = None,
    chunk_store: StoreLike | None = None,
    filters: Iterable[dict[str, JSON] | Numcodec] | None = None,
    cache_metadata: bool | None = None,
    cache_attrs: bool | None = None,
    read_only: bool | None = None,
    object_codec: Codec | None = None,  # TODO: type has changed
    dimension_separator: Literal[".", "/"] | None = None,
    write_empty_chunks: bool | None = None,  # TODO: default has changed
    zarr_format: ZarrFormat | None = None,
    meta_array: Any | None = None,  # TODO: need type
    attributes: dict[str, JSON] | None = None,
    # v3 only
    chunk_shape: tuple[int, ...] | int | None = None,
    chunk_key_encoding: (
        ChunkKeyEncoding
        | tuple[Literal["default"], Literal[".", "/"]]
        | tuple[Literal["v2"], Literal[".", "/"]]
        | None
    ) = None,
    codecs: Iterable[Codec | dict[str, JSON]] | None = None,
    dimension_names: DimensionNamesLike = None,
    storage_options: dict[str, Any] | None = None,
    config: ArrayConfigLike | None = None,
    **kwargs: Any,
) -> AnyArray:
    """Create an array.

    Parameters
    ----------
    shape : int or tuple of ints
        Array shape.
    chunks : int or tuple of ints, optional
        Chunk shape. If True, will be guessed from ``shape`` and ``dtype``. If
        False, will be set to ``shape``, i.e., single chunk for the whole array.
        If an int, the chunk size in each dimension will be given by the value
        of ``chunks``. Default is True.
    dtype : str or dtype, optional
        NumPy dtype.
    compressor : Codec, optional
        Primary compressor to compress chunk data.
        Zarr format 2 only. Zarr format 3 arrays should use ``codecs`` instead.

        If neither ``compressor`` nor ``filters`` are provided, the default compressor
        [`zarr.codecs.ZstdCodec`][] is used.

        If ``compressor`` is set to ``None``, no compression is used.
    fill_value : Any, optional
        Fill value for the array.
    order : {'C', 'F'}, optional
        Deprecated in favor of the ``config`` keyword argument.
        Pass ``{'order': <value>}`` to ``create`` instead of using this parameter.
        Memory layout to be used within each chunk.
        If not specified, the ``array.order`` parameter in the global config will be used.
    store : StoreLike or None, default=None
        StoreLike object to open. See the
        [storage documentation in the user guide][user-guide-store-like]
        for a description of all valid StoreLike values.
    synchronizer : object, optional
        Array synchronizer.
    overwrite : bool, optional
        If True, delete all pre-existing data in ``store`` at ``path`` before
        creating the array.
    path : str, optional
        Path under which array is stored.
    chunk_store : StoreLike or None, default=None
        Separate storage for chunks. If not provided, ``store`` will be used
        for storage of both chunks and metadata.
    filters : Iterable[Codec] | Literal["auto"], optional
        Iterable of filters to apply to each chunk of the array, in order, before serializing that
        chunk to bytes.

        For Zarr format 3, a "filter" is a codec that takes an array and returns an array,
        and these values must be instances of [`zarr.abc.codec.ArrayArrayCodec`][], or a
        dict representations of [`zarr.abc.codec.ArrayArrayCodec`][].

        For Zarr format 2, a "filter" can be any numcodecs codec; you should ensure that the
        order of your filters is consistent with the behavior of each filter.

        The default value of ``"auto"`` instructs Zarr to use a default based on the data
        type of the array and the Zarr format specified. For all data types in Zarr V3, and most
        data types in Zarr V2, the default filters are empty. The only cases where default filters
        are not empty is when the Zarr format is 2, and the data type is a variable-length data type like
        [`zarr.dtype.VariableLengthUTF8`][] or [`zarr.dtype.VariableLengthUTF8`][]. In these cases,
        the default filters contains a single element which is a codec specific to that particular data type.

        To create an array with no filters, provide an empty iterable or the value ``None``.
    cache_metadata : bool, optional
        If True, array configuration metadata will be cached for the
        lifetime of the object. If False, array metadata will be reloaded
        prior to all data access and modification operations (may incur
        overhead depending on storage and data access pattern).
    cache_attrs : bool, optional
        If True (default), user attributes will be cached for attribute read
        operations. If False, user attributes are reloaded from the store prior
        to all attribute read operations.
    read_only : bool, optional
        True if array should be protected against modification.
    object_codec : Codec, optional
        A codec to encode object arrays, only needed if dtype=object.
    dimension_separator : {'.', '/'}, optional
        Separator placed between the dimensions of a chunk.
        Zarr format 2 only. Zarr format 3 arrays should use ``chunk_key_encoding`` instead.
    write_empty_chunks : bool, optional
        Deprecated in favor of the ``config`` keyword argument.
        Pass ``{'write_empty_chunks': <value>}`` to ``create`` instead of using this parameter.
        If True, all chunks will be stored regardless of their
        contents. If False, each chunk is compared to the array's fill value
        prior to storing. If a chunk is uniformly equal to the fill value, then
        that chunk is not be stored, and the store entry for that chunk's key
        is deleted.
    zarr_format : {2, 3, None}, optional
        The Zarr format to use when creating an array. The default is ``None``,
        which instructs Zarr to choose the default Zarr format value defined in the
        runtime configuration.
    meta_array : array-like, optional
        Not implemented.
    attributes : dict[str, JSON], optional
        A dictionary of user attributes to store with the array.
    chunk_shape : int or tuple of ints, optional
        The shape of the Array's chunks (default is None).
        Zarr format 3 only. Zarr format 2 arrays should use `chunks` instead.
    chunk_key_encoding : ChunkKeyEncoding, optional
        A specification of how the chunk keys are represented in storage.
        Zarr format 3 only. Zarr format 2 arrays should use `dimension_separator` instead.
        Default is ``("default", "/")``.
    codecs : Sequence of Codecs or dicts, optional
        An iterable of Codec or dict serializations of Codecs. Zarr V3 only.

        The elements of ``codecs`` specify the transformation from array values to stored bytes.
        Zarr format 3 only. Zarr format 2 arrays should use ``filters`` and ``compressor`` instead.

        If no codecs are provided, default codecs will be used based on the data type of the array.
        For most data types, the default codecs are the tuple ``(BytesCodec(), ZstdCodec())``;
        data types that require a special [`zarr.abc.codec.ArrayBytesCodec`][], like variable-length strings or bytes,
        will use the [`zarr.abc.codec.ArrayBytesCodec`][] required for the data type instead of [`zarr.codecs.BytesCodec`][].
    dimension_names : Iterable[str | None] | None = None
        An iterable of dimension names. Zarr format 3 only.
    storage_options : dict
        If using an fsspec URL to create the store, these will be passed to
        the backend implementation. Ignored otherwise.
    config : ArrayConfigLike, optional
        Runtime configuration of the array. If provided, will override the
        default values from `zarr.config.array`.

    Returns
    -------
    z : Array
        The array.
    """
    return Array(
        sync(
            async_api.create(
                shape=shape,
                chunks=chunks,
                dtype=dtype,
                compressor=compressor,
                fill_value=fill_value,
                order=order,
                store=store,
                synchronizer=synchronizer,
                overwrite=overwrite,
                path=path,
                chunk_store=chunk_store,
                filters=filters,
                cache_metadata=cache_metadata,
                cache_attrs=cache_attrs,
                read_only=read_only,
                object_codec=object_codec,
                dimension_separator=dimension_separator,
                write_empty_chunks=write_empty_chunks,
                zarr_format=zarr_format,
                meta_array=meta_array,
                attributes=attributes,
                chunk_shape=chunk_shape,
                chunk_key_encoding=chunk_key_encoding,
                codecs=codecs,
                dimension_names=dimension_names,
                storage_options=storage_options,
                config=config,
                **kwargs,
            )
        )
    )