def __init__(self, store, path=None, read_only=False, chunk_store=None,
synchronizer=None):
self._store = store
self._path = normalize_storage_path(path)
if self._path:
self._key_prefix = self._path + '/'
else:
self._key_prefix = ''
self._read_only = read_only
if chunk_store is None:
self._chunk_store = store
else:
self._chunk_store = chunk_store
self._synchronizer = synchronizer
# guard conditions
if contains_array(store, path=self._path):
err_contains_array(path)
# initialize metadata
try:
mkey = self._key_prefix + group_meta_key
meta_bytes = store[mkey]
except KeyError:
err_group_not_found(path)
else:
meta = decode_group_metadata(meta_bytes)
self._meta = meta
# setup attributes
akey = self._key_prefix + attrs_key
self._attrs = Attributes(store, key=akey, read_only=read_only,
synchronizer=synchronizer)
def __init__(self, store, path=None, read_only=False, chunk_store=None,
cache_attrs=True, synchronizer=None):
self._store = store
self._chunk_store = chunk_store
self._path = normalize_storage_path(path)
if self._path:
self._key_prefix = self._path + '/'
else:
self._key_prefix = ''
self._read_only = read_only
self._synchronizer = synchronizer
# guard conditions
if contains_array(store, path=self._path):
err_contains_array(path)
# initialize metadata
try:
mkey = self._key_prefix + group_meta_key
meta_bytes = store[mkey]
except KeyError:
err_group_not_found(path)
else:
meta = decode_group_metadata(meta_bytes)
self._meta = meta
# setup attributes
akey = self._key_prefix + attrs_key
self._attrs = Attributes(store, key=akey, read_only=read_only,
cache=cache_attrs, synchronizer=synchronizer)
# setup info
self._info = InfoReporter(self)
def _init_array_metadata(store, shape, chunks=None, dtype=None,
compressor='default',
fill_value=None, order='C', overwrite=False,
path=None, chunk_store=None, filters=None):
# guard conditions
if overwrite:
# attempt to delete any pre-existing items in store
rmdir(store, path)
if chunk_store is not None and chunk_store != store:
rmdir(chunk_store, path)
elif contains_array(store, path):
err_contains_array(path)
elif contains_group(store, path):
err_contains_group(path)
# normalize metadata
shape = normalize_shape(shape)
dtype = np.dtype(dtype)
chunks = normalize_chunks(chunks, shape, dtype.itemsize)
order = normalize_order(order)
# obtain compressor config
if compressor == 'none':
# compatibility
compressor = None
elif compressor == 'default':
compressor = default_compressor
if compressor:
try:
compressor_config = compressor.get_config()
except AttributeError:
err_bad_compressor(compressor)
else:
compressor_config = None
# obtain filters config
if filters:
filters_config = [f.get_config() for f in filters]
else:
filters_config = None
# initialize metadata
meta = dict(shape=shape, chunks=chunks, dtype=dtype,
compressor=compressor_config, fill_value=fill_value,
order=order, filters=filters_config)
key = _path_to_prefix(path) + array_meta_key
store[key] = encode_array_metadata(meta)
# initialize attributes
key = _path_to_prefix(path) + attrs_key
store[key] = json.dumps(dict()).encode('ascii')
def _init_group_metadata(store, overwrite=False, path=None, chunk_store=None):
# guard conditions
if overwrite:
# attempt to delete any pre-existing items in store
rmdir(store, path)
if chunk_store is not None and chunk_store != store:
rmdir(chunk_store, path)
elif contains_array(store, path):
err_contains_array(path)
elif contains_group(store, path):
err_contains_group(path)
# initialize metadata
# N.B., currently no metadata properties are needed, however there may
# be in future
meta = dict()
key = _path_to_prefix(path) + group_meta_key
store[key] = encode_group_metadata(meta)
# initialize attributes
key = _path_to_prefix(path) + attrs_key
store[key] = json.dumps(dict()).encode('ascii')
def _init_group_metadata(store, overwrite=False, path=None, chunk_store=None):
# guard conditions
if overwrite:
# attempt to delete any pre-existing items in store
rmdir(store, path)
if chunk_store is not None and chunk_store != store:
rmdir(chunk_store, path)
elif contains_array(store, path):
err_contains_array(path)
elif contains_group(store, path):
err_contains_group(path)
# initialize metadata
# N.B., currently no metadata properties are needed, however there may
# be in future
meta = dict()
key = _path_to_prefix(path) + group_meta_key
store[key] = encode_group_metadata(meta)
# initialize attributes
key = _path_to_prefix(path) + attrs_key
store[key] = json.dumps(dict()).encode('ascii')
def _init_array_metadata(store,
shape,
chunks=None,
dtype=None,
compressor='default',
fill_value=None,
order='C',
overwrite=False,
path=None,
chunk_store=None,
filters=None):
# guard conditions
if overwrite:
# attempt to delete any pre-existing items in store
rmdir(store, path)
if chunk_store is not None and chunk_store != store:
rmdir(chunk_store, path)
elif contains_array(store, path):
err_contains_array(path)
elif contains_group(store, path):
err_contains_group(path)
# normalize metadata
shape = normalize_shape(shape)
dtype = np.dtype(dtype)
chunks = normalize_chunks(chunks, shape, dtype.itemsize)
order = normalize_order(order)
# obtain compressor config
if compressor == 'none':
# compatibility
compressor = None
elif compressor == 'default':
compressor = default_compressor
if compressor:
try:
compressor_config = compressor.get_config()
except AttributeError:
err_bad_compressor(compressor)
else:
compressor_config = None
# obtain filters config
if filters:
filters_config = [f.get_config() for f in filters]
else:
filters_config = None
# initialize metadata
meta = dict(shape=shape,
chunks=chunks,
dtype=dtype,
compressor=compressor_config,
fill_value=fill_value,
order=order,
filters=filters_config)
key = _path_to_prefix(path) + array_meta_key
store[key] = encode_array_metadata(meta)
# initialize attributes
key = _path_to_prefix(path) + attrs_key
store[key] = json.dumps(dict()).encode('ascii')
def open_group(store,
mode='a',
cache_attrs=True,
synchronizer=None,
path=None):
"""Open a group using file-mode-like semantics.
Parameters
----------
store : MutableMapping or string
Store or path to directory in file system or name of zip file.
mode : {'r', 'r+', 'a', 'w', 'w-'}, optional
Persistence mode: 'r' means read only (must exist); 'r+' means
read/write (must exist); 'a' means read/write (create if doesn't
exist); 'w' means create (overwrite if exists); 'w-' means create
(fail if exists).
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 : string, optional
Group path within store.
Returns
-------
g : zarr.hierarchy.Group
Examples
--------
>>> import zarr
>>> root = zarr.open_group('data/example.zarr', mode='w')
>>> foo = root.create_group('foo')
>>> bar = root.create_group('bar')
>>> root
<zarr.hierarchy.Group '/'>
>>> root2 = zarr.open_group('data/example.zarr', mode='a')
>>> root2
<zarr.hierarchy.Group '/'>
>>> root == root2
True
"""
# handle polymorphic store arg
store = _normalize_store_arg(store)
path = normalize_storage_path(path)
# ensure store is initialized
if mode in ['r', 'r+']:
if contains_array(store, path=path):
err_contains_array(path)
elif not contains_group(store, path=path):
err_group_not_found(path)
elif mode == 'w':
init_group(store, overwrite=True, path=path)
elif mode == 'a':
if contains_array(store, path=path):
err_contains_array(path)
if not contains_group(store, path=path):
init_group(store, path=path)
elif mode in ['w-', 'x']:
if contains_array(store, path=path):
err_contains_array(path)
elif contains_group(store, path=path):
err_contains_group(path)
else:
init_group(store, path=path)
# determine read only status
read_only = mode == 'r'
return Group(store,
read_only=read_only,
cache_attrs=cache_attrs,
synchronizer=synchronizer,
path=path)
def open_group(store=None, mode='a', synchronizer=None, path=None):
"""Open a group using mode-like semantics.
Parameters
----------
store : MutableMapping or string
Store or path to directory in file system.
mode : {'r', 'r+', 'a', 'w', 'w-'}
Persistence mode: 'r' means read only (must exist); 'r+' means
read/write (must exist); 'a' means read/write (create if doesn't
exist); 'w' means create (overwrite if exists); 'w-' means create
(fail if exists).
synchronizer : object, optional
Array synchronizer.
path : string, optional
Group path.
Returns
-------
g : zarr.hierarchy.Group
Examples
--------
>>> import zarr
>>> root = zarr.open_group('example', mode='w')
>>> foo = root.create_group('foo')
>>> bar = root.create_group('bar')
>>> root
Group(/, 2)
groups: 2; bar, foo
store: DirectoryStore
>>> root2 = zarr.open_group('example', mode='a')
>>> root2
Group(/, 2)
groups: 2; bar, foo
store: DirectoryStore
>>> root == root2
True
"""
# handle polymorphic store arg
store = _handle_store_arg(store)
path = normalize_storage_path(path)
# ensure store is initialized
if mode in ['r', 'r+']:
if contains_array(store, path=path):
err_contains_array(path)
elif not contains_group(store, path=path):
err_group_not_found(path)
elif mode == 'w':
init_group(store, overwrite=True, path=path)
elif mode == 'a':
if contains_array(store, path=path):
err_contains_array(path)
if not contains_group(store, path=path):
init_group(store, path=path)
elif mode in ['w-', 'x']:
if contains_array(store, path=path):
err_contains_array(path)
elif contains_group(store, path=path):
err_contains_group(path)
else:
init_group(store, path=path)
# determine read only status
read_only = mode == 'r'
return Group(store, read_only=read_only, synchronizer=synchronizer,
path=path)
def _init_array_metadata(store,
shape,
chunks=None,
dtype=None,
compressor='default',
fill_value=None,
order='C',
overwrite=False,
path=None,
chunk_store=None,
filters=None):
# guard conditions
if overwrite:
# attempt to delete any pre-existing items in store
rmdir(store, path)
if chunk_store is not None:
rmdir(chunk_store, path)
elif contains_array(store, path):
err_contains_array(path)
elif contains_group(store, path):
err_contains_group(path)
# normalize metadata
shape = normalize_shape(shape)
dtype = np.dtype(dtype)
if dtype.kind in 'mM':
raise ValueError(
'datetime64 and timedelta64 dtypes are not currently supported; '
'please store the data using int64 instead')
chunks = normalize_chunks(chunks, shape, dtype.itemsize)
order = normalize_order(order)
fill_value = normalize_fill_value(fill_value, dtype)
# compressor prep
if shape == ():
# no point in compressing a 0-dimensional array, only a single value
compressor = None
elif compressor == 'none':
# compatibility
compressor = None
elif compressor == 'default':
compressor = default_compressor
# obtain compressor config
compressor_config = None
if compressor:
try:
compressor_config = compressor.get_config()
except AttributeError:
err_bad_compressor(compressor)
# obtain filters config
if filters:
filters_config = [f.get_config() for f in filters]
else:
filters_config = None
# initialize metadata
meta = dict(shape=shape,
chunks=chunks,
dtype=dtype,
compressor=compressor_config,
fill_value=fill_value,
order=order,
filters=filters_config)
key = _path_to_prefix(path) + array_meta_key
store[key] = encode_array_metadata(meta)
# initialize attributes
key = _path_to_prefix(path) + attrs_key
store[key] = json.dumps(dict()).encode('ascii')
def open_array(store,
mode='a',
shape=None,
chunks=True,
dtype=None,
compressor='default',
fill_value=0,
order='C',
synchronizer=None,
filters=None,
cache_metadata=True,
cache_attrs=True,
path=None,
object_codec=None,
**kwargs):
"""Open an array using file-mode-like semantics.
Parameters
----------
store : MutableMapping or string
Store or path to directory in file system or name of zip file.
mode : {'r', 'r+', 'a', 'w', 'w-'}, optional
Persistence mode: 'r' means read only (must exist); 'r+' means
read/write (must exist); 'a' means read/write (create if doesn't
exist); 'w' means create (overwrite if exists); 'w-' means create
(fail if exists).
shape : int or tuple of ints, optional
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.
dtype : string or dtype, optional
NumPy dtype.
compressor : Codec, optional
Primary compressor.
fill_value : object, optional
Default value to use for uninitialized portions of the array.
order : {'C', 'F'}, optional
Memory layout to be used within each chunk.
synchronizer : object, optional
Array synchronizer.
filters : sequence, optional
Sequence of filters to use to encode chunk data prior to compression.
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.
path : string, optional
Array path within store.
object_codec : Codec, optional
A codec to encode object arrays, only needed if dtype=object.
Returns
-------
z : zarr.core.Array
Examples
--------
>>> import numpy as np
>>> import zarr
>>> z1 = zarr.open_array('data/example.zarr', mode='w', shape=(10000, 10000),
... chunks=(1000, 1000), fill_value=0)
>>> z1[:] = np.arange(100000000).reshape(10000, 10000)
>>> z1
<zarr.core.Array (10000, 10000) float64>
>>> z2 = zarr.open_array('data/example.zarr', mode='r')
>>> z2
<zarr.core.Array (10000, 10000) float64 read-only>
>>> np.all(z1[:] == z2[:])
True
Notes
-----
There is no need to close an array. Data are automatically flushed to the
file system.
"""
# use same mode semantics as h5py
# r : read only, must exist
# r+ : read/write, must exist
# w : create, delete if exists
# w- or x : create, fail if exists
# a : read/write if exists, create otherwise (default)
# handle polymorphic store arg
store = normalize_store_arg(store, clobber=(mode == 'w'))
path = normalize_storage_path(path)
# API compatibility with h5py
compressor, fill_value = _kwargs_compat(compressor, fill_value, kwargs)
# ensure fill_value of correct type
if fill_value is not None:
fill_value = np.array(fill_value, dtype=dtype)[()]
# ensure store is initialized
if mode in ['r', 'r+']:
if contains_group(store, path=path):
err_contains_group(path)
elif not contains_array(store, path=path):
err_array_not_found(path)
elif mode == 'w':
init_array(store,
shape=shape,
chunks=chunks,
dtype=dtype,
compressor=compressor,
fill_value=fill_value,
order=order,
filters=filters,
overwrite=True,
path=path,
object_codec=object_codec)
elif mode == 'a':
if contains_group(store, path=path):
err_contains_group(path)
elif not contains_array(store, path=path):
init_array(store,
shape=shape,
chunks=chunks,
dtype=dtype,
compressor=compressor,
fill_value=fill_value,
order=order,
filters=filters,
path=path,
object_codec=object_codec)
elif mode in ['w-', 'x']:
if contains_group(store, path=path):
err_contains_group(path)
elif contains_array(store, path=path):
err_contains_array(path)
else:
init_array(store,
shape=shape,
chunks=chunks,
dtype=dtype,
compressor=compressor,
fill_value=fill_value,
order=order,
filters=filters,
path=path,
object_codec=object_codec)
# determine read only status
read_only = mode == 'r'
# instantiate array
z = Array(store,
read_only=read_only,
synchronizer=synchronizer,
cache_metadata=cache_metadata,
cache_attrs=cache_attrs,
path=path)
return z
def open_array(store, mode='a', shape=None, chunks=True, dtype=None, compressor='default',
fill_value=0, order='C', synchronizer=None, filters=None,
cache_metadata=True, cache_attrs=True, path=None, object_codec=None,
**kwargs):
"""Open an array using file-mode-like semantics.
Parameters
----------
store : MutableMapping or string
Store or path to directory in file system or name of zip file.
mode : {'r', 'r+', 'a', 'w', 'w-'}, optional
Persistence mode: 'r' means read only (must exist); 'r+' means
read/write (must exist); 'a' means read/write (create if doesn't
exist); 'w' means create (overwrite if exists); 'w-' means create
(fail if exists).
shape : int or tuple of ints, optional
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.
dtype : string or dtype, optional
NumPy dtype.
compressor : Codec, optional
Primary compressor.
fill_value : object, optional
Default value to use for uninitialized portions of the array.
order : {'C', 'F'}, optional
Memory layout to be used within each chunk.
synchronizer : object, optional
Array synchronizer.
filters : sequence, optional
Sequence of filters to use to encode chunk data prior to compression.
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.
path : string, optional
Array path within store.
object_codec : Codec, optional
A codec to encode object arrays, only needed if dtype=object.
Returns
-------
z : zarr.core.Array
Examples
--------
>>> import numpy as np
>>> import zarr
>>> z1 = zarr.open_array('data/example.zarr', mode='w', shape=(10000, 10000),
... chunks=(1000, 1000), fill_value=0)
>>> z1[:] = np.arange(100000000).reshape(10000, 10000)
>>> z1
<zarr.core.Array (10000, 10000) float64>
>>> z2 = zarr.open_array('data/example.zarr', mode='r')
>>> z2
<zarr.core.Array (10000, 10000) float64 read-only>
>>> np.all(z1[:] == z2[:])
True
Notes
-----
There is no need to close an array. Data are automatically flushed to the
file system.
"""
# use same mode semantics as h5py
# r : read only, must exist
# r+ : read/write, must exist
# w : create, delete if exists
# w- or x : create, fail if exists
# a : read/write if exists, create otherwise (default)
# handle polymorphic store arg
store = normalize_store_arg(store, clobber=(mode == 'w'))
path = normalize_storage_path(path)
# API compatibility with h5py
compressor, fill_value = _kwargs_compat(compressor, fill_value, kwargs)
# ensure fill_value of correct type
if fill_value is not None:
fill_value = np.array(fill_value, dtype=dtype)[()]
# ensure store is initialized
if mode in ['r', 'r+']:
if contains_group(store, path=path):
err_contains_group(path)
elif not contains_array(store, path=path):
err_array_not_found(path)
elif mode == 'w':
init_array(store, shape=shape, chunks=chunks, dtype=dtype,
compressor=compressor, fill_value=fill_value,
order=order, filters=filters, overwrite=True, path=path,
object_codec=object_codec)
elif mode == 'a':
if contains_group(store, path=path):
err_contains_group(path)
elif not contains_array(store, path=path):
init_array(store, shape=shape, chunks=chunks, dtype=dtype,
compressor=compressor, fill_value=fill_value,
order=order, filters=filters, path=path,
object_codec=object_codec)
elif mode in ['w-', 'x']:
if contains_group(store, path=path):
err_contains_group(path)
elif contains_array(store, path=path):
err_contains_array(path)
else:
init_array(store, shape=shape, chunks=chunks, dtype=dtype,
compressor=compressor, fill_value=fill_value,
order=order, filters=filters, path=path,
object_codec=object_codec)
# determine read only status
read_only = mode == 'r'
# instantiate array
z = Array(store, read_only=read_only, synchronizer=synchronizer,
cache_metadata=cache_metadata, cache_attrs=cache_attrs, path=path)
return z
def open_group(store=None, mode='a', synchronizer=None, path=None):
"""Open a group using mode-like semantics.
Parameters
----------
store : MutableMapping or string
Store or path to directory in file system.
mode : {'r', 'r+', 'a', 'w', 'w-'}
Persistence mode: 'r' means read only (must exist); 'r+' means
read/write (must exist); 'a' means read/write (create if doesn't
exist); 'w' means create (overwrite if exists); 'w-' means create
(fail if exists).
synchronizer : object, optional
Array synchronizer.
path : string, optional
Group path.
Returns
-------
g : zarr.hierarchy.Group
Examples
--------
>>> import zarr
>>> root = zarr.open_group('example', mode='w')
>>> foo = root.create_group('foo')
>>> bar = root.create_group('bar')
>>> root
Group(/, 2)
groups: 2; bar, foo
store: DirectoryStore
>>> root2 = zarr.open_group('example', mode='a')
>>> root2
Group(/, 2)
groups: 2; bar, foo
store: DirectoryStore
>>> root == root2
True
"""
# handle polymorphic store arg
store = _handle_store_arg(store)
path = normalize_storage_path(path)
# ensure store is initialized
if mode in ['r', 'r+']:
if contains_array(store, path=path):
err_contains_array(path)
elif not contains_group(store, path=path):
err_group_not_found(path)
elif mode == 'w':
init_group(store, overwrite=True, path=path)
elif mode == 'a':
if contains_array(store, path=path):
err_contains_array(path)
if not contains_group(store, path=path):
init_group(store, path=path)
elif mode in ['w-', 'x']:
if contains_array(store, path=path):
err_contains_array(path)
elif contains_group(store, path=path):
err_contains_group(path)
else:
init_group(store, path=path)
# determine read only status
read_only = mode == 'r'
return Group(store,
read_only=read_only,
synchronizer=synchronizer,
path=path)
def open_array(store=None, mode='a', shape=None, chunks=None, dtype=None,
compressor='default', fill_value=0, order='C',
synchronizer=None, filters=None, cache_metadata=True,
path=None, **kwargs):
"""Open array using mode-like semantics.
Parameters
----------
store : MutableMapping or string
Store or path to directory in file system.
mode : {'r', 'r+', 'a', 'w', 'w-'}
Persistence mode: 'r' means read only (must exist); 'r+' means
read/write (must exist); 'a' means read/write (create if doesn't
exist); 'w' means create (overwrite if exists); 'w-' means create
(fail if exists).
shape : int or tuple of ints
Array shape.
chunks : int or tuple of ints, optional
Chunk shape. If not provided, will be guessed from `shape` and `dtype`.
dtype : string or dtype, optional
NumPy dtype.
compressor : Codec, optional
Primary compressor.
fill_value : object
Default value to use for uninitialized portions of the array.
order : {'C', 'F'}, optional
Memory layout to be used within each chunk.
synchronizer : object, optional
Array synchronizer.
filters : sequence, optional
Sequence of filters to use to encode chunk data prior to compression.
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).
path : string, optional
Array path.
Returns
-------
z : zarr.core.Array
Examples
--------
>>> import numpy as np
>>> import zarr
>>> z1 = zarr.open_array('example.zarr', mode='w', shape=(10000, 10000),
... chunks=(1000, 1000), fill_value=0)
>>> z1[:] = np.arange(100000000).reshape(10000, 10000)
>>> z1
Array((10000, 10000), float64, chunks=(1000, 1000), order=C)
nbytes: 762.9M; nbytes_stored: 23.0M; ratio: 33.2; initialized: 100/100
compressor: Blosc(cname='lz4', clevel=5, shuffle=1)
store: DirectoryStore
>>> z2 = zarr.open_array('example.zarr', mode='r')
>>> z2
Array((10000, 10000), float64, chunks=(1000, 1000), order=C)
nbytes: 762.9M; nbytes_stored: 23.0M; ratio: 33.2; initialized: 100/100
compressor: Blosc(cname='lz4', clevel=5, shuffle=1)
store: DirectoryStore
>>> np.all(z1[:] == z2[:])
True
Notes
-----
There is no need to close an array. Data are automatically flushed to the
file system.
""" # flake8: noqa
# use same mode semantics as h5py
# r : read only, must exist
# r+ : read/write, must exist
# w : create, delete if exists
# w- or x : create, fail if exists
# a : read/write if exists, create otherwise (default)
# handle polymorphic store arg
store = _handle_store_arg(store)
path = normalize_storage_path(path)
# compatibility
compressor, fill_value = _handle_kwargs(compressor, fill_value, kwargs)
# ensure store is initialized
if mode in ['r', 'r+']:
if contains_group(store, path=path):
err_contains_group(path)
elif not contains_array(store, path=path):
err_array_not_found(path)
elif mode == 'w':
init_array(store, shape=shape, chunks=chunks, dtype=dtype,
compressor=compressor, fill_value=fill_value,
order=order, filters=filters, overwrite=True, path=path)
elif mode == 'a':
if contains_group(store, path=path):
err_contains_group(path)
elif not contains_array(store, path=path):
init_array(store, shape=shape, chunks=chunks, dtype=dtype,
compressor=compressor, fill_value=fill_value,
order=order, filters=filters, path=path)
elif mode in ['w-', 'x']:
if contains_group(store, path=path):
err_contains_group(path)
elif contains_array(store, path=path):
err_contains_array(path)
else:
init_array(store, shape=shape, chunks=chunks, dtype=dtype,
compressor=compressor, fill_value=fill_value,
order=order, filters=filters, path=path)
# determine read only status
read_only = mode == 'r'
# instantiate array
z = Array(store, read_only=read_only, synchronizer=synchronizer,
cache_metadata=cache_metadata, path=path)
return z
def open_group(store, mode='a', cache_attrs=True, synchronizer=None, path=None):
"""Open a group using file-mode-like semantics.
Parameters
----------
store : MutableMapping or string
Store or path to directory in file system or name of zip file.
mode : {'r', 'r+', 'a', 'w', 'w-'}, optional
Persistence mode: 'r' means read only (must exist); 'r+' means
read/write (must exist); 'a' means read/write (create if doesn't
exist); 'w' means create (overwrite if exists); 'w-' means create
(fail if exists).
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 : string, optional
Group path within store.
Returns
-------
g : zarr.hierarchy.Group
Examples
--------
>>> import zarr
>>> root = zarr.open_group('data/example.zarr', mode='w')
>>> foo = root.create_group('foo')
>>> bar = root.create_group('bar')
>>> root
<zarr.hierarchy.Group '/'>
>>> root2 = zarr.open_group('data/example.zarr', mode='a')
>>> root2
<zarr.hierarchy.Group '/'>
>>> root == root2
True
"""
# handle polymorphic store arg
store = _normalize_store_arg(store)
path = normalize_storage_path(path)
# ensure store is initialized
if mode in ['r', 'r+']:
if contains_array(store, path=path):
err_contains_array(path)
elif not contains_group(store, path=path):
err_group_not_found(path)
elif mode == 'w':
init_group(store, overwrite=True, path=path)
elif mode == 'a':
if contains_array(store, path=path):
err_contains_array(path)
if not contains_group(store, path=path):
init_group(store, path=path)
elif mode in ['w-', 'x']:
if contains_array(store, path=path):
err_contains_array(path)
elif contains_group(store, path=path):
err_contains_group(path)
else:
init_group(store, path=path)
# determine read only status
read_only = mode == 'r'
return Group(store, read_only=read_only, cache_attrs=cache_attrs,
synchronizer=synchronizer, path=path)