def open(uri=None, mode='a'):
"""Open a Blaze object via an `uri` (Uniform Resource Identifier).
Parameters
----------
uri : str
Specifies the URI for the Blaze object. It can be a regular file too.
mode : the open mode (string)
Specifies the mode in which the object is opened. The supported
values are:
* 'r' for read-only
* 'w' for emptying the previous underlying data
* 'a' for allowing read/write on top of existing data
Returns
-------
out : an Array or Table object.
"""
ARRAY = 1
TABLE = 2
if uri is None:
source = CArraySource()
else:
uri = urlparse(uri)
if uri.scheme == 'carray':
path = os.path.join(uri.netloc, uri.path[1:])
parms = params(storage=path)
source = CArraySource(params=parms)
structure = ARRAY
if uri.scheme == 'ctable':
path = os.path.join(uri.netloc, uri.path[1:])
parms = params(storage=path)
source = CTableSource(params=parms)
structure = TABLE
elif uri.scheme == 'sqlite':
path = os.path.join(uri.netloc, uri.path[1:])
parms = params(storage=path or None)
source = SqliteSource(params=parms)
structure = TABLE
else:
# Default is to treat the URI as a regular path
parms = params(storage=uri.path)
source = CArraySource(params=parms)
structure = ARRAY
# Don't want a deferred array (yet)
# return NDArray(source)
if structure == ARRAY:
return Array(source)
elif structure == TABLE:
return NDTable(source)
def fromiter(iterable, dshape, params=None):
""" Create an Array and fill it with values from `iterable`.
Parameters
----------
iterable : iterable object
An iterable object providing data for the carray.
dshape : str, blaze.dshape instance
Specifies the datashape of the outcome object. Only 1d shapes
are supported right now. When the `iterator` should return an
unknown number of items, a ``TypeVar`` can be used.
params : blaze.params object
Any parameter supported by the backend library.
Returns
-------
out : an Array object.
"""
if isinstance(dshape, basestring):
dshape = _dshape(dshape)
shape, dtype = dshape.parameters[:-1], dshape.parameters[-1]
# Check the shape part
if len(shape) > 1:
raise ValueError("shape can be only 1-dimensional")
length = shape[0]
count = -1
if type(length) == TypeVar:
count = -1
elif type(length) == Fixed:
count = length.val
dtype = dtype.to_dtype()
# Now, create the Array itself (using the carray backend)
cparams, rootdir, format_flavor = to_cparams(params or _params())
if rootdir is not None:
carray.fromiter(iterable,
dtype,
count=count,
rootdir=rootdir,
cparams=cparams)
return open(rootdir)
else:
ica = carray.fromiter(iterable, dtype, count=count, cparams=cparams)
source = CArraySource(ica, params=params)
return Array(source)
def open(uri, mode='a', eclass=_eclass.manifest):
"""Open a Blaze object via an `uri` (Uniform Resource Identifier).
Parameters
----------
uri : str
Specifies the URI for the Blaze object. It can be a regular file too.
The URL scheme indicates the storage type:
* carray: Chunked array
* ctable: Chunked table
* sqlite: SQLite table (the URI 'sqlite://' creates in-memory table)
If no URI scheme is given, carray is assumed.
mode : the open mode (string)
Specifies the mode in which the object is opened. The supported
values are:
* 'r' for read-only
* 'w' for emptying the previous underlying data
* 'a' for allowing read/write on top of existing data
Returns
-------
out : an Array or Table object.
"""
ARRAY = 1
TABLE = 2
uri = urlparse(uri)
path = uri.netloc + uri.path
parms = params(storage=path)
if uri.scheme == 'carray':
source = CArraySource(params=parms)
structure = ARRAY
elif uri.scheme == 'ctable':
source = CTableSource(params=parms)
structure = TABLE
elif uri.scheme == 'sqlite':
# Empty path means memory storage
parms = params(storage=path or None)
source = SqliteSource(params=parms)
structure = TABLE
else:
# Default is to treat the URI as a regular path
parms = params(storage=path)
source = CArraySource(params=parms)
structure = ARRAY
# Don't want a deferred array (yet)
# return NDArray(source)
if structure == ARRAY:
if eclass is _eclass.manifest:
return Array(source)
elif eclass is _eclass.delayed:
return NDArray(source)
elif structure == TABLE:
if eclass is _eclass.manifest:
return Table(source)
elif eclass is _eclass.delayed:
return NDTable(source)
