Source code for tables.unimplemented

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#
# License: BSD
# Created: January 14, 2004
# Author:  Francesc Alted - faltet@pytables.com
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# $Id$
#
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"""Here is defined the UnImplemented class."""

import warnings

from . import hdf5extension
from .utils import SizeType
from .node import Node
from .leaf import Leaf


[docs]class UnImplemented(hdf5extension.UnImplemented, Leaf): """This class represents datasets not supported by PyTables in an HDF5 file. When reading a generic HDF5 file (i.e. one that has not been created with PyTables, but with some other HDF5 library based tool), chances are that the specific combination of datatypes or dataspaces in some dataset might not be supported by PyTables yet. In such a case, this dataset will be mapped into an UnImplemented instance and the user will still be able to access the complete object tree of the generic HDF5 file. The user will also be able to *read and write the attributes* of the dataset, *access some of its metadata*, and perform *certain hierarchy manipulation operations* like deleting or moving (but not copying) the node. Of course, the user will not be able to read the actual data on it. This is an elegant way to allow users to work with generic HDF5 files despite the fact that some of its datasets are not supported by PyTables. However, if you are really interested in having full access to an unimplemented dataset, please get in contact with the developer team. This class does not have any public instance variables or methods, except those inherited from the Leaf class (see :ref:`LeafClassDescr`). """ # Class identifier. _c_classid = 'UNIMPLEMENTED' def __init__(self, parentnode, name): """Create the `UnImplemented` instance.""" # UnImplemented objects always come from opening an existing node # (they can not be created). self._v_new = False """Is this the first time the node has been created?""" self.nrows = SizeType(0) """The length of the first dimension of the data.""" self.shape = (SizeType(0),) """The shape of the stored data.""" self.byteorder = None """The endianness of data in memory ('big', 'little' or 'irrelevant').""" super().__init__(parentnode, name) def _g_open(self): (self.shape, self.byteorder, object_id) = self._open_unimplemented() try: self.nrows = SizeType(self.shape[0]) except IndexError: self.nrows = SizeType(0) return object_id def _g_copy(self, newparent, newname, recursive, _log=True, **kwargs): """Do nothing. This method does nothing, but a ``UserWarning`` is issued. Please note that this method *does not return a new node*, but ``None``. """ warnings.warn( "UnImplemented node %r does not know how to copy itself; skipping" % (self._v_pathname,)) return None # Can you see it? def _f_copy(self, newparent=None, newname=None, overwrite=False, recursive=False, createparents=False, **kwargs): """Do nothing. This method does nothing, since `UnImplemented` nodes can not be copied. However, a ``UserWarning`` is issued. Please note that this method *does not return a new node*, but ``None``. """ # This also does nothing but warn. self._g_copy(newparent, newname, recursive, **kwargs) return None # Can you see it? def __repr__(self): return """{} NOTE: <The UnImplemented object represents a PyTables unimplemented dataset present in the '{}' HDF5 file. If you want to see this kind of HDF5 dataset implemented in PyTables, please contact the developers.> """.format(str(self), self._v_file.filename)
# Classes reported as H5G_UNKNOWN by HDF5
[docs]class Unknown(Node): """This class represents nodes reported as *unknown* by the underlying HDF5 library. This class does not have any public instance variables or methods, except those inherited from the Node class. """ # Class identifier _c_classid = 'UNKNOWN' def __init__(self, parentnode, name): """Create the `Unknown` instance.""" self._v_new = False super().__init__(parentnode, name) def _g_new(self, parentnode, name, init=False): pass def _g_open(self): return 0 def _g_copy(self, newparent, newname, recursive, _log=True, **kwargs): # Silently avoid doing copies of unknown nodes return None def _g_delete(self, parent): pass def __str__(self): pathname = self._v_pathname classname = self.__class__.__name__ return "{} ({})".format(pathname, classname) def __repr__(self): return """%s NOTE: <The Unknown object represents a node which is reported as unknown by the underlying HDF5 library, but that might be supported in more recent HDF5 versions.> """ % (str(self))
# These are listed here for backward compatibility with PyTables 0.9.x indexes class OldIndexArray(UnImplemented): _c_classid = 'IndexArray'