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create

zarr.array

array(data: ArrayLike | Array, **kwargs: Any) -> Array

Create an array filled with data.

Parameters:

  • data (array_like) –

    The data to fill the array with.

  • **kwargs (Any, default: {} ) –

    Passed through to create.

Returns:

  • array ( Array ) –

    The new array.

Source code in zarr/api/synchronous.py
def array(data: npt.ArrayLike | Array, **kwargs: Any) -> Array:
    """Create an array filled with `data`.

    Parameters
    ----------
    data : array_like
        The data to fill the array with.
    **kwargs
        Passed through to [`create`][zarr.api.asynchronous.create].

    Returns
    -------
    array : Array
        The new array.
    """

    return Array(sync(async_api.array(data=data, **kwargs)))

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_version: ZarrFormat | 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: DimensionNames = None,
    storage_options: dict[str, Any] | None = None,
    config: ArrayConfigLike | None = None,
    **kwargs: Any,
) -> Array

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 ) –

    Store or path to directory in file system or name of zip file.

  • 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 the order if your filters is consistent with the behavior of each filter.

    The default value of "auto" instructs Zarr to use a default used 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_version: ZarrFormat | None = None,  # deprecated
    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: DimensionNames = None,
    storage_options: dict[str, Any] | None = None,
    config: ArrayConfigLike | None = None,
    **kwargs: Any,
) -> Array:
    """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
        Store or path to directory in file system or name of zip file.
    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
        the order if your filters is consistent with the behavior of each filter.

        The default value of ``"auto"`` instructs Zarr to use a default used 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_version=zarr_version,
                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,
            )
        )
    )

zarr.create_array

create_array(
    store: StoreLike,
    *,
    name: str | None = None,
    shape: ShapeLike | None = None,
    dtype: ZDTypeLike | None = None,
    data: ndarray[Any, dtype[Any]] | None = None,
    chunks: tuple[int, ...] | Literal["auto"] = "auto",
    shards: ShardsLike | None = None,
    filters: FiltersLike = "auto",
    compressors: CompressorsLike = "auto",
    serializer: SerializerLike = "auto",
    fill_value: Any | None = DEFAULT_FILL_VALUE,
    order: MemoryOrder | None = None,
    zarr_format: ZarrFormat | None = 3,
    attributes: dict[str, JSON] | None = None,
    chunk_key_encoding: ChunkKeyEncodingLike | None = None,
    dimension_names: DimensionNames = None,
    storage_options: dict[str, Any] | None = None,
    overwrite: bool = False,
    config: ArrayConfigLike | None = None,
    write_data: bool = True,
) -> Array

Create an array.

This function wraps zarr.core.array.create_array.

Parameters:

  • store (StoreLike) –

    Store or path to directory in file system or name of zip file.

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

    The name of the array within the store. If name is None, the array will be located at the root of the store.

  • shape (ShapeLike, default: None ) –

    Shape of the array. Must be None if data is provided.

  • dtype (ZDTypeLike | None, default: None ) –

    Data type of the array. Must be None if data is provided.

  • data (ndarray, default: None ) –

    Array-like data to use for initializing the array. If this parameter is provided, the shape and dtype parameters must be None.

  • chunks (tuple[int, ...] | Literal['auto'], default: "auto" ) –

    Chunk shape of the array. If chunks is "auto", a chunk shape is guessed based on the shape of the array and the dtype.

  • shards (tuple[int, ...], default: None ) –

    Shard shape of the array. The default value of None results in no sharding at all.

  • filters (Iterable[Codec] | Literal['auto'], default: 'auto' ) –

    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 the order if your filters is consistent with the behavior of each filter.

    The default value of "auto" instructs Zarr to use a default used 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.

  • compressors (Iterable[Codec], default: 'auto' ) –

    List of compressors to apply to the array. Compressors are applied in order, and after any filters are applied (if any are specified) and the data is serialized into bytes.

    For Zarr format 3, a "compressor" is a codec that takes a bytestream, and returns another bytestream. Multiple compressors my be provided for Zarr format 3. If no compressors are provided, a default set of compressors will be used. These defaults can be changed by modifying the value of array.v3_default_compressors in zarr.config. Use None to omit default compressors.

    For Zarr format 2, a "compressor" can be any numcodecs codec. Only a single compressor may be provided for Zarr format 2. If no compressor is provided, a default compressor will be used. in zarr.config. Use None to omit the default compressor.

  • serializer (dict[str, JSON] | ArrayBytesCodec, default: 'auto' ) –

    Array-to-bytes codec to use for encoding the array data. Zarr format 3 only. Zarr format 2 arrays use implicit array-to-bytes conversion. If no serializer is provided, a default serializer will be used. These defaults can be changed by modifying the value of array.v3_default_serializer in zarr.config.

  • fill_value (Any, default: DEFAULT_FILL_VALUE ) –

    Fill value for the array.

  • order (('C', 'F'), default: "C" ) –

    The memory of the array (default is "C"). For Zarr format 2, this parameter sets the memory order of the array. For Zarr format 3, this parameter is deprecated, because memory order is a runtime parameter for Zarr format 3 arrays. The recommended way to specify the memory order for Zarr format 3 arrays is via the config parameter, e.g. {'config': 'C'}. If no order is provided, a default order will be used. This default can be changed by modifying the value of array.order in zarr.config.

  • zarr_format ((2, 3), default: 2 ) –

    The zarr format to use when saving.

  • attributes (dict, default: None ) –

    Attributes for the array.

  • chunk_key_encoding (ChunkKeyEncodingLike, default: None ) –

    A specification of how the chunk keys are represented in storage. For Zarr format 3, the default is {"name": "default", "separator": "/"}}. For Zarr format 2, the default is {"name": "v2", "separator": "."}}.

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

    The names of the dimensions (default is None). Zarr format 3 only. Zarr format 2 arrays should not use this parameter.

  • storage_options (dict, default: None ) –

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

  • overwrite (bool, default: False ) –

    Whether to overwrite an array with the same name in the store, if one exists. If True, all existing paths in the store will be deleted.

  • config (ArrayConfigLike, default: None ) –

    Runtime configuration for the array.

  • write_data (bool, default: True ) –

    If a pre-existing array-like object was provided to this function via the data parameter then write_data determines whether the values in that array-like object should be written to the Zarr array created by this function. If write_data is False, then the array will be left empty.

Returns:

Examples:

>>> import zarr
>>> store = zarr.storage.MemoryStore()
>>> arr = await zarr.create_array(
>>>     store=store,
>>>     shape=(100,100),
>>>     chunks=(10,10),
>>>     dtype='i4',
>>>     fill_value=0)
<Array memory://140349042942400 shape=(100, 100) dtype=int32>
Source code in zarr/api/synchronous.py
def create_array(
    store: StoreLike,
    *,
    name: str | None = None,
    shape: ShapeLike | None = None,
    dtype: ZDTypeLike | None = None,
    data: np.ndarray[Any, np.dtype[Any]] | None = None,
    chunks: tuple[int, ...] | Literal["auto"] = "auto",
    shards: ShardsLike | None = None,
    filters: FiltersLike = "auto",
    compressors: CompressorsLike = "auto",
    serializer: SerializerLike = "auto",
    fill_value: Any | None = DEFAULT_FILL_VALUE,
    order: MemoryOrder | None = None,
    zarr_format: ZarrFormat | None = 3,
    attributes: dict[str, JSON] | None = None,
    chunk_key_encoding: ChunkKeyEncodingLike | None = None,
    dimension_names: DimensionNames = None,
    storage_options: dict[str, Any] | None = None,
    overwrite: bool = False,
    config: ArrayConfigLike | None = None,
    write_data: bool = True,
) -> Array:
    """Create an array.

    This function wraps [zarr.core.array.create_array][].

    Parameters
    ----------
    store : StoreLike
        Store or path to directory in file system or name of zip file.
    name : str or None, optional
        The name of the array within the store. If ``name`` is ``None``, the array will be located
        at the root of the store.
    shape : ShapeLike, optional
        Shape of the array. Must be ``None`` if ``data`` is provided.
    dtype : ZDTypeLike | None
        Data type of the array. Must be ``None`` if ``data`` is provided.
    data : np.ndarray, optional
        Array-like data to use for initializing the array. If this parameter is provided, the
        ``shape`` and ``dtype`` parameters must be ``None``.
    chunks : tuple[int, ...] | Literal["auto"], default="auto"
        Chunk shape of the array.
        If chunks is "auto", a chunk shape is guessed based on the shape of the array and the dtype.
    shards : tuple[int, ...], optional
        Shard shape of the array. The default value of ``None`` results in no sharding at all.
    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
        the order if your filters is consistent with the behavior of each filter.

        The default value of ``"auto"`` instructs Zarr to use a default used 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``.
    compressors : Iterable[Codec], optional
        List of compressors to apply to the array. Compressors are applied in order, and after any
        filters are applied (if any are specified) and the data is serialized into bytes.

        For Zarr format 3, a "compressor" is a codec that takes a bytestream, and
        returns another bytestream. Multiple compressors my be provided for Zarr format 3.
        If no ``compressors`` are provided, a default set of compressors will be used.
        These defaults can be changed by modifying the value of ``array.v3_default_compressors``
        in [`zarr.config`][zarr.config].
        Use ``None`` to omit default compressors.

        For Zarr format 2, a "compressor" can be any numcodecs codec. Only a single compressor may
        be provided for Zarr format 2.
        If no ``compressor`` is provided, a default compressor will be used.
        in [`zarr.config`][zarr.config].
        Use ``None`` to omit the default compressor.
    serializer : dict[str, JSON] | ArrayBytesCodec, optional
        Array-to-bytes codec to use for encoding the array data.
        Zarr format 3 only. Zarr format 2 arrays use implicit array-to-bytes conversion.
        If no ``serializer`` is provided, a default serializer will be used.
        These defaults can be changed by modifying the value of ``array.v3_default_serializer``
        in [`zarr.config`][zarr.config].
    fill_value : Any, optional
        Fill value for the array.
    order : {"C", "F"}, optional
        The memory of the array (default is "C").
        For Zarr format 2, this parameter sets the memory order of the array.
        For Zarr format 3, this parameter is deprecated, because memory order
        is a runtime parameter for Zarr format 3 arrays. The recommended way to specify the memory
        order for Zarr format 3 arrays is via the ``config`` parameter, e.g. ``{'config': 'C'}``.
        If no ``order`` is provided, a default order will be used.
        This default can be changed by modifying the value of ``array.order`` in [`zarr.config`][zarr.config].
    zarr_format : {2, 3}, optional
        The zarr format to use when saving.
    attributes : dict, optional
        Attributes for the array.
    chunk_key_encoding : ChunkKeyEncodingLike, optional
        A specification of how the chunk keys are represented in storage.
        For Zarr format 3, the default is ``{"name": "default", "separator": "/"}}``.
        For Zarr format 2, the default is ``{"name": "v2", "separator": "."}}``.
    dimension_names : Iterable[str], optional
        The names of the dimensions (default is None).
        Zarr format 3 only. Zarr format 2 arrays should not use this parameter.
    storage_options : dict, optional
        If using an fsspec URL to create the store, these will be passed to the backend implementation.
        Ignored otherwise.
    overwrite : bool, default False
        Whether to overwrite an array with the same name in the store, if one exists.
        If ``True``, all existing paths in the store will be deleted.
    config : ArrayConfigLike, optional
        Runtime configuration for the array.
    write_data : bool
        If a pre-existing array-like object was provided to this function via the ``data`` parameter
        then ``write_data`` determines whether the values in that array-like object should be
        written to the Zarr array created by this function. If ``write_data`` is ``False``, then the
        array will be left empty.

    Returns
    -------
    Array
        The array.

    Examples
    --------
    >>> import zarr
    >>> store = zarr.storage.MemoryStore()
    >>> arr = await zarr.create_array(
    >>>     store=store,
    >>>     shape=(100,100),
    >>>     chunks=(10,10),
    >>>     dtype='i4',
    >>>     fill_value=0)
    <Array memory://140349042942400 shape=(100, 100) dtype=int32>
    """
    return Array(
        sync(
            zarr.core.array.create_array(
                store,
                name=name,
                shape=shape,
                dtype=dtype,
                data=data,
                chunks=chunks,
                shards=shards,
                filters=filters,
                compressors=compressors,
                serializer=serializer,
                fill_value=fill_value,
                order=order,
                zarr_format=zarr_format,
                attributes=attributes,
                chunk_key_encoding=chunk_key_encoding,
                dimension_names=dimension_names,
                storage_options=storage_options,
                overwrite=overwrite,
                config=config,
                write_data=write_data,
            )
        )
    )

zarr.create_group

create_group(
    store: StoreLike,
    *,
    path: str | None = None,
    zarr_format: ZarrFormat | None = None,
    overwrite: bool = False,
    attributes: dict[str, Any] | None = None,
    storage_options: dict[str, Any] | None = None,
) -> Group

Create a group.

Parameters:

  • store (StoreLike) –

    Store or path to directory in file system or name of zip file.

  • path (str, default: None ) –

    Group path within store.

  • overwrite (bool, default: False ) –

    If True, pre-existing data at path will be deleted before creating the group.

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

    The zarr format to use when saving. If no zarr_format is provided, the default format will be used. This default can be changed by modifying the value of default_zarr_format in zarr.config.

  • storage_options (dict, default: None ) –

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

Returns:

  • Group

    The new group.

Source code in zarr/api/synchronous.py
def create_group(
    store: StoreLike,
    *,
    path: str | None = None,
    zarr_format: ZarrFormat | None = None,
    overwrite: bool = False,
    attributes: dict[str, Any] | None = None,
    storage_options: dict[str, Any] | None = None,
) -> Group:
    """Create a group.

    Parameters
    ----------
    store : StoreLike
        Store or path to directory in file system or name of zip file.
    path : str, optional
        Group path within store.
    overwrite : bool, optional
        If True, pre-existing data at ``path`` will be deleted before
        creating the group.
    zarr_format : {2, 3, None}, optional
        The zarr format to use when saving.
        If no ``zarr_format`` is provided, the default format will be used.
        This default can be changed by modifying the value of ``default_zarr_format``
        in [`zarr.config`][zarr.config].
    storage_options : dict
        If using an fsspec URL to create the store, these will be passed to
        the backend implementation. Ignored otherwise.

    Returns
    -------
    Group
        The new group.
    """
    return Group(
        sync(
            async_api.create_group(
                store=store,
                path=path,
                overwrite=overwrite,
                storage_options=storage_options,
                zarr_format=zarr_format,
                attributes=attributes,
            )
        )
    )

zarr.create_hierarchy

create_hierarchy(
    *,
    store: Store,
    nodes: dict[
        str,
        GroupMetadata | ArrayV2Metadata | ArrayV3Metadata,
    ],
    overwrite: bool = False,
) -> Iterator[tuple[str, Group | Array]]

Create a complete zarr hierarchy from a collection of metadata objects.

This function will parse its input to ensure that the hierarchy is complete. Any implicit groups will be inserted as needed. For example, an input like {'a/b': GroupMetadata} will be parsed to {'': GroupMetadata, 'a': GroupMetadata, 'b': Groupmetadata}

After input parsing, this function then creates all the nodes in the hierarchy concurrently.

Arrays and Groups are yielded in the order they are created. This order is not stable and should not be relied on.

Parameters:

  • store (Store) –

    The storage backend to use.

  • nodes (dict[str, GroupMetadata | ArrayV3Metadata | ArrayV2Metadata]) –

    A dictionary defining the hierarchy. The keys are the paths of the nodes in the hierarchy, relative to the root of the Store. The root of the store can be specified with the empty string ''. The values are instances of GroupMetadata or ArrayMetadata. Note that all values must have the same zarr_format -- it is an error to mix zarr versions in the same hierarchy.

    Leading "/" characters from keys will be removed.

  • overwrite (bool, default: False ) –

    Whether to overwrite existing nodes. Defaults to False, in which case an error is raised instead of overwriting an existing array or group.

    This function will not erase an existing group unless that group is explicitly named in nodes. If nodes defines implicit groups, e.g. {`'a/b/c': GroupMetadata}, and a group already exists at path a, then this function will leave the group at a as-is.

Yields:

  • tuple[str, Group | Array]

    This function yields (path, node) pairs, in the order the nodes were created.

Examples:

>>> from zarr import create_hierarchy
>>> from zarr.storage import MemoryStore
>>> from zarr.core.group import GroupMetadata
>>> store = MemoryStore()
>>> nodes = {'a': GroupMetadata(attributes={'name': 'leaf'})}
>>> nodes_created = dict(create_hierarchy(store=store, nodes=nodes))
>>> print(nodes)
# {'a': GroupMetadata(attributes={'name': 'leaf'}, zarr_format=3, consolidated_metadata=None, node_type='group')}
Source code in zarr/core/sync_group.py
def create_hierarchy(
    *,
    store: Store,
    nodes: dict[str, GroupMetadata | ArrayV2Metadata | ArrayV3Metadata],
    overwrite: bool = False,
) -> Iterator[tuple[str, Group | Array]]:
    """
    Create a complete zarr hierarchy from a collection of metadata objects.

    This function will parse its input to ensure that the hierarchy is complete. Any implicit groups
    will be inserted as needed. For example, an input like
    ```{'a/b': GroupMetadata}``` will be parsed to
    ```{'': GroupMetadata, 'a': GroupMetadata, 'b': Groupmetadata}```

    After input parsing, this function then creates all the nodes in the hierarchy concurrently.

    Arrays and Groups are yielded in the order they are created. This order is not stable and
    should not be relied on.

    Parameters
    ----------
    store : Store
        The storage backend to use.
    nodes : dict[str, GroupMetadata | ArrayV3Metadata | ArrayV2Metadata]
        A dictionary defining the hierarchy. The keys are the paths of the nodes in the hierarchy,
        relative to the root of the ``Store``. The root of the store can be specified with the empty
        string ``''``. The values are instances of ``GroupMetadata`` or ``ArrayMetadata``. Note that
        all values must have the same ``zarr_format`` -- it is an error to mix zarr versions in the
        same hierarchy.

        Leading "/" characters from keys will be removed.
    overwrite : bool
        Whether to overwrite existing nodes. Defaults to ``False``, in which case an error is
        raised instead of overwriting an existing array or group.

        This function will not erase an existing group unless that group is explicitly named in
        ``nodes``. If ``nodes`` defines implicit groups, e.g. ``{`'a/b/c': GroupMetadata}``, and a
        group already exists at path ``a``, then this function will leave the group at ``a`` as-is.

    Yields
    ------
    tuple[str, Group | Array]
        This function yields (path, node) pairs, in the order the nodes were created.

    Examples
    --------
    >>> from zarr import create_hierarchy
    >>> from zarr.storage import MemoryStore
    >>> from zarr.core.group import GroupMetadata

    >>> store = MemoryStore()
    >>> nodes = {'a': GroupMetadata(attributes={'name': 'leaf'})}
    >>> nodes_created = dict(create_hierarchy(store=store, nodes=nodes))
    >>> print(nodes)
    # {'a': GroupMetadata(attributes={'name': 'leaf'}, zarr_format=3, consolidated_metadata=None, node_type='group')}
    """
    coro = create_hierarchy_async(store=store, nodes=nodes, overwrite=overwrite)

    for key, value in sync(_collect_aiterator(coro)):
        yield key, _parse_async_node(value)

zarr.empty

empty(shape: tuple[int, ...], **kwargs: Any) -> Array

Create an empty array with the specified shape. The contents will be filled with the array's fill value or zeros if no fill value is provided.

Parameters:

  • shape (int or tuple of int) –

    Shape of the empty array.

  • **kwargs (Any, default: {} ) –

    Keyword arguments passed to create.

Returns:

  • Array

    The new array.

Notes

The contents of an empty Zarr array are not defined. On attempting to retrieve data from an empty Zarr array, any values may be returned, and these are not guaranteed to be stable from one access to the next.

Source code in zarr/api/synchronous.py
def empty(shape: tuple[int, ...], **kwargs: Any) -> Array:
    """Create an empty array with the specified shape. The contents will be filled with the
    array's fill value or zeros if no fill value is provided.

    Parameters
    ----------
    shape : int or tuple of int
        Shape of the empty array.
    **kwargs
        Keyword arguments passed to [`create`][zarr.api.asynchronous.create].

    Returns
    -------
    Array
        The new array.

    Notes
    -----
    The contents of an empty Zarr array are not defined. On attempting to
    retrieve data from an empty Zarr array, any values may be returned,
    and these are not guaranteed to be stable from one access to the next.
    """
    return Array(sync(async_api.empty(shape, **kwargs)))

zarr.empty_like

empty_like(a: ArrayLike, **kwargs: Any) -> Array

Create an empty array like another array. The contents will be filled with the array's fill value or zeros if no fill value is provided.

Parameters:

  • a (array - like) –

    The array to create an empty array like.

  • **kwargs (Any, default: {} ) –

    Keyword arguments passed to create.

Returns:

  • Array

    The new array.

Notes

The contents of an empty Zarr array are not defined. On attempting to retrieve data from an empty Zarr array, any values may be returned, and these are not guaranteed to be stable from one access to the next.

Source code in zarr/api/synchronous.py
def empty_like(a: ArrayLike, **kwargs: Any) -> Array:
    """Create an empty array like another array. The contents will be filled with the
    array's fill value or zeros if no fill value is provided.

    Parameters
    ----------
    a : array-like
        The array to create an empty array like.
    **kwargs
        Keyword arguments passed to [`create`][zarr.api.asynchronous.create].

    Returns
    -------
    Array
        The new array.

    Notes
    -----
    The contents of an empty Zarr array are not defined. On attempting to
    retrieve data from an empty Zarr array, any values may be returned,
    and these are not guaranteed to be stable from one access to the next.
    """
    return Array(sync(async_api.empty_like(a, **kwargs)))

zarr.full

full(
    shape: tuple[int, ...], fill_value: Any, **kwargs: Any
) -> Array

Create an array with a default fill value.

Parameters:

  • shape (int or tuple of int) –

    Shape of the empty array.

  • fill_value (scalar) –

    Fill value.

  • **kwargs (Any, default: {} ) –

    Keyword arguments passed to create.

Returns:

  • Array

    The new array.

Source code in zarr/api/synchronous.py
def full(shape: tuple[int, ...], fill_value: Any, **kwargs: Any) -> Array:
    """Create an array with a default fill value.

    Parameters
    ----------
    shape : int or tuple of int
        Shape of the empty array.
    fill_value : scalar
        Fill value.
    **kwargs
        Keyword arguments passed to [`create`][zarr.api.asynchronous.create].

    Returns
    -------
    Array
        The new array.
    """
    return Array(sync(async_api.full(shape=shape, fill_value=fill_value, **kwargs)))

zarr.full_like

full_like(a: ArrayLike, **kwargs: Any) -> Array

Create a filled array like another array.

Parameters:

Returns:

  • Array

    The new array.

Source code in zarr/api/synchronous.py
def full_like(a: ArrayLike, **kwargs: Any) -> Array:
    """Create a filled array like another array.

    Parameters
    ----------
    a : array-like
        The array to create an empty array like.
    **kwargs
        Keyword arguments passed to [`zarr.api.asynchronous.create`][].

    Returns
    -------
    Array
        The new array.
    """
    return Array(sync(async_api.full_like(a, **kwargs)))

zarr.from_array

from_array(
    store: StoreLike,
    *,
    data: Array | ArrayLike,
    write_data: bool = True,
    name: str | None = None,
    chunks: Literal["auto", "keep"]
    | tuple[int, ...] = "keep",
    shards: ShardsLike | None | Literal["keep"] = "keep",
    filters: FiltersLike | Literal["keep"] = "keep",
    compressors: CompressorsLike | Literal["keep"] = "keep",
    serializer: SerializerLike | Literal["keep"] = "keep",
    fill_value: Any | None = DEFAULT_FILL_VALUE,
    order: MemoryOrder | None = None,
    zarr_format: ZarrFormat | None = None,
    attributes: dict[str, JSON] | None = None,
    chunk_key_encoding: ChunkKeyEncodingLike | None = None,
    dimension_names: DimensionNames = None,
    storage_options: dict[str, Any] | None = None,
    overwrite: bool = False,
    config: ArrayConfigLike | None = None,
) -> Array

Create an array from an existing array or array-like.

Parameters:

  • store (StoreLike) –

    Store or path to directory in file system or name of zip file.

  • data (Array | array - like) –

    The array to copy.

  • write_data (bool, default: True ) –

    Whether to copy the data from the input array to the new array. If write_data is False, the new array will be created with the same metadata as the input array, but without any data.

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

    The name of the array within the store. If name is None, the array will be located at the root of the store.

  • chunks (tuple[int, ...] or 'auto' or 'keep', default: 'keep' ) –

    Chunk shape of the array. Following values are supported:

    • "auto": Automatically determine the chunk shape based on the array's shape and dtype.
    • "keep": Retain the chunk shape of the data array if it is a zarr Array.
    • tuple[int, ...]: A tuple of integers representing the chunk shape.

    If not specified, defaults to "keep" if data is a zarr Array, otherwise "auto".

  • shards (tuple[int, ...], default: 'keep' ) –

    Shard shape of the array. Following values are supported:

    • "auto": Automatically determine the shard shape based on the array's shape and chunk shape.
    • "keep": Retain the shard shape of the data array if it is a zarr Array.
    • tuple[int, ...]: A tuple of integers representing the shard shape.
    • None: No sharding.

    If not specified, defaults to "keep" if data is a zarr Array, otherwise None.

  • filters (Iterable[Codec] | Literal['auto', 'keep'], default: 'keep' ) –

    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 the order if your filters is consistent with the behavior of each filter.

    The default value of "keep" instructs Zarr to infer filters from data. If that inference is not possible, Zarr will fall back to the behavior specified by "auto", which is to choose default filters 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 the empty tuple (). 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 is a tuple with 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.

  • compressors (Iterable[Codec] or 'auto' or 'keep', default: 'keep' ) –

    List of compressors to apply to the array. Compressors are applied in order, and after any filters are applied (if any are specified) and the data is serialized into bytes.

    For Zarr format 3, a "compressor" is a codec that takes a bytestream, and returns another bytestream. Multiple compressors my be provided for Zarr format 3.

    For Zarr format 2, a "compressor" can be any numcodecs codec. Only a single compressor may be provided for Zarr format 2.

    Following values are supported:

    • Iterable[Codec]: List of compressors to apply to the array.
    • "auto": Automatically determine the compressors based on the array's dtype.
    • "keep": Retain the compressors of the input array if it is a zarr Array.

    If no compressors are provided, defaults to "keep" if data is a zarr Array, otherwise "auto".

  • serializer (dict[str, JSON] | ArrayBytesCodec or 'auto' or 'keep', default: 'keep' ) –

    Array-to-bytes codec to use for encoding the array data. Zarr format 3 only. Zarr format 2 arrays use implicit array-to-bytes conversion.

    Following values are supported:

    • dict[str, JSON]: A dict representation of an ArrayBytesCodec.
    • ArrayBytesCodec: An instance of ArrayBytesCodec.
    • "auto": a default serializer will be used. These defaults can be changed by modifying the value of array.v3_default_serializer in zarr.config.
    • "keep": Retain the serializer of the input array if it is a zarr Array.
  • fill_value (Any, default: DEFAULT_FILL_VALUE ) –

    Fill value for the array. If not specified, defaults to the fill value of the data array.

  • order (('C', 'F'), default: "C" ) –

    The memory of the array (default is "C"). For Zarr format 2, this parameter sets the memory order of the array. For Zarr format 3, this parameter is deprecated, because memory order is a runtime parameter for Zarr format 3 arrays. The recommended way to specify the memory order for Zarr format 3 arrays is via the config parameter, e.g. {'config': 'C'}. If not specified, defaults to the memory order of the data array.

  • zarr_format ((2, 3), default: 2 ) –

    The zarr format to use when saving. If not specified, defaults to the zarr format of the data array.

  • attributes (dict, default: None ) –

    Attributes for the array. If not specified, defaults to the attributes of the data array.

  • chunk_key_encoding (ChunkKeyEncoding, default: None ) –

    A specification of how the chunk keys are represented in storage. For Zarr format 3, the default is {"name": "default", "separator": "/"}}. For Zarr format 2, the default is {"name": "v2", "separator": "."}}. If not specified and the data array has the same zarr format as the target array, the chunk key encoding of the data array is used.

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

    The names of the dimensions (default is None). Zarr format 3 only. Zarr format 2 arrays should not use this parameter. If not specified, defaults to the dimension names of the data array.

  • storage_options (dict, default: None ) –

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

  • overwrite (bool, default: False ) –

    Whether to overwrite an array with the same name in the store, if one exists.

  • config (ArrayConfig or ArrayConfigLike, default: None ) –

    Runtime configuration for the array.

Returns:

Examples:

Create an array from an existing Array::

>>> import zarr
>>> store = zarr.storage.MemoryStore()
>>> store2 = zarr.storage.LocalStore('example.zarr')
>>> arr = zarr.create_array(
>>>     store=store,
>>>     shape=(100,100),
>>>     chunks=(10,10),
>>>     dtype='int32',
>>>     fill_value=0)
>>> arr2 = zarr.from_array(store2, data=arr)
<Array file://example.zarr shape=(100, 100) dtype=int32>

Create an array from an existing NumPy array::

>>> import numpy as np
>>> arr3 = zarr.from_array(
        zarr.storage.MemoryStore(),
>>>     data=np.arange(10000, dtype='i4').reshape(100, 100),
>>> )
<Array memory://125477403529984 shape=(100, 100) dtype=int32>

Create an array from any array-like object::

>>> arr4 = zarr.from_array(
>>>     zarr.storage.MemoryStore(),
>>>     data=[[1, 2], [3, 4]],
>>> )
<Array memory://125477392154368 shape=(2, 2) dtype=int64>
>>> arr4[...]
array([[1, 2],[3, 4]])

Create an array from an existing Array without copying the data::

>>> arr5 = zarr.from_array(
>>>     zarr.storage.MemoryStore(),
>>>     data=arr4,
>>>     write_data=False,
>>> )
<Array memory://140678602965568 shape=(2, 2) dtype=int64>
>>> arr5[...]
array([[0, 0],[0, 0]])
Source code in zarr/api/synchronous.py
def from_array(
    store: StoreLike,
    *,
    data: Array | npt.ArrayLike,
    write_data: bool = True,
    name: str | None = None,
    chunks: Literal["auto", "keep"] | tuple[int, ...] = "keep",
    shards: ShardsLike | None | Literal["keep"] = "keep",
    filters: FiltersLike | Literal["keep"] = "keep",
    compressors: CompressorsLike | Literal["keep"] = "keep",
    serializer: SerializerLike | Literal["keep"] = "keep",
    fill_value: Any | None = DEFAULT_FILL_VALUE,
    order: MemoryOrder | None = None,
    zarr_format: ZarrFormat | None = None,
    attributes: dict[str, JSON] | None = None,
    chunk_key_encoding: ChunkKeyEncodingLike | None = None,
    dimension_names: DimensionNames = None,
    storage_options: dict[str, Any] | None = None,
    overwrite: bool = False,
    config: ArrayConfigLike | None = None,
) -> Array:
    """Create an array from an existing array or array-like.

    Parameters
    ----------
    store : StoreLike
        Store or path to directory in file system or name of zip file.
    data : Array | array-like
        The array to copy.
    write_data : bool, default True
        Whether to copy the data from the input array to the new array.
        If ``write_data`` is ``False``, the new array will be created with the same metadata as the
        input array, but without any data.
    name : str or None, optional
        The name of the array within the store. If ``name`` is ``None``, the array will be located
        at the root of the store.
    chunks : tuple[int, ...] or "auto" or "keep", optional
        Chunk shape of the array.
        Following values are supported:

        - "auto": Automatically determine the chunk shape based on the array's shape and dtype.
        - "keep": Retain the chunk shape of the data array if it is a zarr Array.
        - tuple[int, ...]: A tuple of integers representing the chunk shape.

        If not specified, defaults to "keep" if data is a zarr Array, otherwise "auto".
    shards : tuple[int, ...], optional
        Shard shape of the array.
        Following values are supported:

        - "auto": Automatically determine the shard shape based on the array's shape and chunk shape.
        - "keep": Retain the shard shape of the data array if it is a zarr Array.
        - tuple[int, ...]: A tuple of integers representing the shard shape.
        - None: No sharding.

        If not specified, defaults to "keep" if data is a zarr Array, otherwise None.
    filters : Iterable[Codec] | Literal["auto", "keep"], 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
        the order if your filters is consistent with the behavior of each filter.

        The default value of ``"keep"`` instructs Zarr to infer ``filters`` from ``data``.
        If that inference is not possible, Zarr will fall back to the behavior specified by ``"auto"``,
        which is to choose default filters 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 the empty tuple ``()``.
        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 is a tuple with 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``.
    compressors : Iterable[Codec] or "auto" or "keep", optional
        List of compressors to apply to the array. Compressors are applied in order, and after any
        filters are applied (if any are specified) and the data is serialized into bytes.

        For Zarr format 3, a "compressor" is a codec that takes a bytestream, and
        returns another bytestream. Multiple compressors my be provided for Zarr format 3.

        For Zarr format 2, a "compressor" can be any numcodecs codec. Only a single compressor may
        be provided for Zarr format 2.

        Following values are supported:

        - Iterable[Codec]: List of compressors to apply to the array.
        - "auto": Automatically determine the compressors based on the array's dtype.
        - "keep": Retain the compressors of the input array if it is a zarr Array.

        If no ``compressors`` are provided, defaults to "keep" if data is a zarr Array, otherwise "auto".
    serializer : dict[str, JSON] | ArrayBytesCodec or "auto" or "keep", optional
        Array-to-bytes codec to use for encoding the array data.
        Zarr format 3 only. Zarr format 2 arrays use implicit array-to-bytes conversion.

        Following values are supported:

        - dict[str, JSON]: A dict representation of an ``ArrayBytesCodec``.
        - ArrayBytesCodec: An instance of ``ArrayBytesCodec``.
        - "auto": a default serializer will be used. These defaults can be changed by modifying the value of
          ``array.v3_default_serializer`` in [`zarr.config`][zarr.config].
        - "keep": Retain the serializer of the input array if it is a zarr Array.

    fill_value : Any, optional
        Fill value for the array.
        If not specified, defaults to the fill value of the data array.
    order : {"C", "F"}, optional
        The memory of the array (default is "C").
        For Zarr format 2, this parameter sets the memory order of the array.
        For Zarr format 3, this parameter is deprecated, because memory order
        is a runtime parameter for Zarr format 3 arrays. The recommended way to specify the memory
        order for Zarr format 3 arrays is via the ``config`` parameter, e.g. ``{'config': 'C'}``.
        If not specified, defaults to the memory order of the data array.
    zarr_format : {2, 3}, optional
        The zarr format to use when saving.
        If not specified, defaults to the zarr format of the data array.
    attributes : dict, optional
        Attributes for the array.
        If not specified, defaults to the attributes of the data array.
    chunk_key_encoding : ChunkKeyEncoding, optional
        A specification of how the chunk keys are represented in storage.
        For Zarr format 3, the default is ``{"name": "default", "separator": "/"}}``.
        For Zarr format 2, the default is ``{"name": "v2", "separator": "."}}``.
        If not specified and the data array has the same zarr format as the target array,
        the chunk key encoding of the data array is used.
    dimension_names : Iterable[str | None] | None
        The names of the dimensions (default is None).
        Zarr format 3 only. Zarr format 2 arrays should not use this parameter.
        If not specified, defaults to the dimension names of the data array.
    storage_options : dict, optional
        If using an fsspec URL to create the store, these will be passed to the backend implementation.
        Ignored otherwise.
    overwrite : bool, default False
        Whether to overwrite an array with the same name in the store, if one exists.
    config : ArrayConfig or ArrayConfigLike, optional
        Runtime configuration for the array.

    Returns
    -------
    Array
        The array.

    Examples
    --------
    Create an array from an existing Array::

        >>> import zarr
        >>> store = zarr.storage.MemoryStore()
        >>> store2 = zarr.storage.LocalStore('example.zarr')
        >>> arr = zarr.create_array(
        >>>     store=store,
        >>>     shape=(100,100),
        >>>     chunks=(10,10),
        >>>     dtype='int32',
        >>>     fill_value=0)
        >>> arr2 = zarr.from_array(store2, data=arr)
        <Array file://example.zarr shape=(100, 100) dtype=int32>

    Create an array from an existing NumPy array::

        >>> import numpy as np
        >>> arr3 = zarr.from_array(
                zarr.storage.MemoryStore(),
        >>>     data=np.arange(10000, dtype='i4').reshape(100, 100),
        >>> )
        <Array memory://125477403529984 shape=(100, 100) dtype=int32>

    Create an array from any array-like object::

        >>> arr4 = zarr.from_array(
        >>>     zarr.storage.MemoryStore(),
        >>>     data=[[1, 2], [3, 4]],
        >>> )
        <Array memory://125477392154368 shape=(2, 2) dtype=int64>
        >>> arr4[...]
        array([[1, 2],[3, 4]])

    Create an array from an existing Array without copying the data::

        >>> arr5 = zarr.from_array(
        >>>     zarr.storage.MemoryStore(),
        >>>     data=arr4,
        >>>     write_data=False,
        >>> )
        <Array memory://140678602965568 shape=(2, 2) dtype=int64>
        >>> arr5[...]
        array([[0, 0],[0, 0]])
    """
    return Array(
        sync(
            zarr.core.array.from_array(
                store,
                data=data,
                write_data=write_data,
                name=name,
                chunks=chunks,
                shards=shards,
                filters=filters,
                compressors=compressors,
                serializer=serializer,
                fill_value=fill_value,
                order=order,
                zarr_format=zarr_format,
                attributes=attributes,
                chunk_key_encoding=chunk_key_encoding,
                dimension_names=dimension_names,
                storage_options=storage_options,
                overwrite=overwrite,
                config=config,
            )
        )
    )

zarr.group

group(
    store: StoreLike | None = None,
    *,
    overwrite: bool = False,
    chunk_store: StoreLike | None = None,
    cache_attrs: bool | None = None,
    synchronizer: Any | None = None,
    path: str | None = None,
    zarr_version: ZarrFormat | None = None,
    zarr_format: ZarrFormat | None = None,
    meta_array: Any | None = None,
    attributes: dict[str, JSON] | None = None,
    storage_options: dict[str, Any] | None = None,
) -> Group

Create a group.

Parameters:

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

    Store or path to directory in file system or name of zip file.

  • overwrite (bool, default: False ) –

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

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

    Separate storage for chunks. Not implemented.

  • 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.

  • synchronizer (object, default: None ) –

    Array synchronizer.

  • path (str, default: None ) –

    Group path within store.

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

    An array instance to use for determining arrays to create and return to users. Use numpy.empty(()) by default.

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

    The zarr format to use when saving.

  • storage_options (dict, default: None ) –

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

Returns:

  • g ( Group ) –

    The new group.

Source code in zarr/api/synchronous.py
def group(
    store: StoreLike | None = None,
    *,
    overwrite: bool = False,
    chunk_store: StoreLike | None = None,  # not used
    cache_attrs: bool | None = None,  # not used, default changed
    synchronizer: Any | None = None,  # not used
    path: str | None = None,
    zarr_version: ZarrFormat | None = None,  # deprecated
    zarr_format: ZarrFormat | None = None,
    meta_array: Any | None = None,  # not used
    attributes: dict[str, JSON] | None = None,
    storage_options: dict[str, Any] | None = None,
) -> Group:
    """Create a group.

    Parameters
    ----------
    store : StoreLike or None, default=None
        Store or path to directory in file system or name of zip file.
    overwrite : bool, optional
        If True, delete any pre-existing data in `store` at `path` before
        creating the group.
    chunk_store : StoreLike or None, default=None
        Separate storage for chunks. Not implemented.
    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.
    synchronizer : object, optional
        Array synchronizer.
    path : str, optional
        Group path within store.
    meta_array : array-like, optional
        An array instance to use for determining arrays to create and return
        to users. Use `numpy.empty(())` by default.
    zarr_format : {2, 3, None}, optional
        The zarr format to use when saving.
    storage_options : dict
        If using an fsspec URL to create the store, these will be passed to
        the backend implementation. Ignored otherwise.

    Returns
    -------
    g : Group
        The new group.
    """
    return Group(
        sync(
            async_api.group(
                store=store,
                overwrite=overwrite,
                chunk_store=chunk_store,
                cache_attrs=cache_attrs,
                synchronizer=synchronizer,
                path=path,
                zarr_version=zarr_version,
                zarr_format=zarr_format,
                meta_array=meta_array,
                attributes=attributes,
                storage_options=storage_options,
            )
        )
    )

zarr.ones

ones(shape: tuple[int, ...], **kwargs: Any) -> Array

Create an array with a fill value of one.

Parameters:

Returns:

  • Array

    The new array.

Source code in zarr/api/synchronous.py
def ones(shape: tuple[int, ...], **kwargs: Any) -> Array:
    """Create an array with a fill value of one.

    Parameters
    ----------
    shape : int or tuple of int
        Shape of the empty array.
    **kwargs
        Keyword arguments passed to [`zarr.api.asynchronous.create`][].

    Returns
    -------
    Array
        The new array.
    """
    return Array(sync(async_api.ones(shape, **kwargs)))

zarr.ones_like

ones_like(a: ArrayLike, **kwargs: Any) -> Array

Create an array of ones like another array.

Parameters:

Returns:

  • Array

    The new array.

Source code in zarr/api/synchronous.py
def ones_like(a: ArrayLike, **kwargs: Any) -> Array:
    """Create an array of ones like another array.

    Parameters
    ----------
    a : array-like
        The array to create an empty array like.
    **kwargs
        Keyword arguments passed to [`zarr.api.asynchronous.create`][].

    Returns
    -------
    Array
        The new array.
    """
    return Array(sync(async_api.ones_like(a, **kwargs)))

zarr.zeros

zeros(shape: tuple[int, ...], **kwargs: Any) -> Array

Create an array with a fill value of zero.

Parameters:

Returns:

  • Array

    The new array.

Source code in zarr/api/synchronous.py
def zeros(shape: tuple[int, ...], **kwargs: Any) -> Array:
    """Create an array with a fill value of zero.

    Parameters
    ----------
    shape : int or tuple of int
        Shape of the empty array.
    **kwargs
        Keyword arguments passed to [`zarr.api.asynchronous.create`][].

    Returns
    -------
    Array
        The new array.
    """
    return Array(sync(async_api.zeros(shape=shape, **kwargs)))

zarr.zeros_like

zeros_like(a: ArrayLike, **kwargs: Any) -> Array

Create an array of zeros like another array.

Parameters:

  • a (array - like) –

    The array to create an empty array like.

  • **kwargs (Any, default: {} ) –

    Keyword arguments passed to create.

Returns:

  • Array

    The new array.

Source code in zarr/api/synchronous.py
def zeros_like(a: ArrayLike, **kwargs: Any) -> Array:
    """Create an array of zeros like another array.

    Parameters
    ----------
    a : array-like
        The array to create an empty array like.
    **kwargs
        Keyword arguments passed to [`create`][zarr.api.asynchronous.create].

    Returns
    -------
    Array
        The new array.
    """
    return Array(sync(async_api.zeros_like(a, **kwargs)))