def get_data(self, **kwargs):
"""
.. versionchanged:: 0.1.12
Read the data. This is only possible if a datasource is specified and
any kind of IOExtension or IOInterface is activated. By default,
the builtin :class:`IOExtension <metacatalog.ext.io.extension.IOExtension>`
is activated since version 0.1.12.
"""
if self.datasource is None:
raise MetadataMissingError('Entry need datasource information')
try:
# check if an io_extension is set
if self.io_extension is not None:
return self.io_extension.read(**kwargs)
# if no extension instance, maybe an interface class is set
elif self.io_interface is not None:
reader = self.io_interface.get_reader(self.datasource)
return reader(self, self.datasource, **kwargs)
else:
raise IOOperationNotFoundError(
"No IO interface activated. Run metacatalog.ext.extension('io', InterfaceClass) to register"
)
except IOOperationNotFoundError as e:
print('[ERROR]: Operation not possible.\n%s' % str(e))
return None
def append_data(self, data, **kwargs):
"""
.. versionadded:: 0.1.12
Append data. This is only possible if a datasource is specified and
any kind of IOExtension or IOInterface is activated. By default,
the builtin :class:`IOExtension <metacatalog.ext.io.extension.IOExtension>`
is activated since version 0.1.12.
For the default interface, the datasource type and data type determine
where the data will be stored and how the data has to look like.
You can easily inherit from the
:class:`IOExtension <metacatalog.ext.io.extension.IOExtension>` to
customize read and write behaviour. If you import i.e. a timeseries to
the same database as metacatalog, you will need to prepared data to
to only hold an datetime index and the data to be stored.
"""
if self.datasource is None:
raise MetadataMissingError('Entry need datasource information')
try:
# check if an io_extension is set
if self.io_extension is not None:
return self.io_extension.append(data, **kwargs)
# if no extension instance, maybe an interface class is set
elif self.io_interface is not None:
appender = self.io_interface.get_appender(self.datasource)
return appender(self, self.datasource, data, **kwargs)
else:
raise IOOperationNotFoundError("No IO interface activated. Run metacatalog.ext.extension('io', InterfaceClass) to register")
except IOOperationNotFoundError as e:
print('[ERROR]: Operation not possible.\n%s' % str(e))
return None
def create_datasource(self,
path: str,
type,
datatype,
commit=False,
**args):
"""
"""
#
if self.datasource is not None:
raise MetadataMissingError(
'Datasource already exists. You can edit that one.')
# get a session
session = object_session(self)
# load the datasource type
if isinstance(type, int):
ds_type = api.find_datasource_type(session=session,
id=type,
return_iterator=True).one()
elif isinstance(type, str):
ds_type = api.find_datasource_type(session=session,
name=type,
return_iterator=True).first()
else:
raise AttributeError('type has to be of type int or str')
# TODO need the API for DataTypes here!!
dtype = session.query(
models.DataType).filter(models.DataType.name == datatype).one()
# build the datasource object
ds = models.DataSource(type=ds_type, datatype=dtype, path=path)
# add the args
ds.save_args_from_dict(args)
# append to self
self.datasource = ds
if commit:
try:
session.add(self)
session.commit()
except Exception as e:
session.rollback()
raise e
# return
return ds
def delete_data(self, delete_source=False, **kwargs):
"""
.. versionadded:: 0.1.12
Delete data. This is only possible if a datasource is specified and
any kind of IOExtension or IOInterface is activated. By default,
the builtin :class:`IOExtension <metacatalog.ext.io.extension.IOExtension>`
is activated since version 0.1.12.
For the default interface, the datasource type and data type determine
where the data is stored and how the data will be delted.
You can easily inherit from the
:class:`IOExtension <metacatalog.ext.io.extension.IOExtension>` to
customize read and write behaviour.
Parameters
----------
delete_source : bool
If True, the DataSource will be deleted as well after the data
has been deleted.
"""
if self.datasource is None:
raise MetadataMissingError('Entry need datasource information')
kwargs['delete_source'] = delete_source
try:
# check if an io_extension is set
if self.io_extension is not None:
return self.io_extension.delete(**kwargs)
# if no extension instance, maybe an interface class is set
elif self.io_interface is not None:
deleter = self.io_interface.get_deleter(self.datasource)
return deleter(self, self.datasource, **kwargs)
else:
raise IOOperationNotFoundError(
"No IO interface activated. Run metacatalog.ext.extension('io', InterfaceClass) to register"
)
except IOOperationNotFoundError as e:
print('[ERROR]: Operation not possible.\n%s' % str(e))
return None