def require_dataset(dataset, check_installed=True, purpose=None):
"""Helper function to resolve a dataset.
This function tries to resolve a dataset given an input argument,
or based on the process' working directory, if `None` is given.
Parameters
----------
dataset : None or path or Dataset
Some value identifying a dataset or `None`. In the latter case
a dataset will be searched based on the process working directory.
check_installed : bool, optional
If True, an optional check whether the resolved dataset is
properly installed will be performed.
purpose : str, optional
This string will be inserted in error messages to make them more
informative. The pattern is "... dataset for <STRING>".
Returns
-------
Dataset
If a dataset could be determined.
Raises
------
NoDatasetFound
If not dataset could be determined.
"""
if dataset is not None and not isinstance(dataset, Dataset):
dataset = Dataset(dataset)
if dataset is None: # possible scenario of cmdline calls
dspath = get_dataset_root(getpwd())
if not dspath:
raise NoDatasetFound(
"No dataset found at '{}'{}. Specify a dataset to work with "
"by providing its path via the `dataset` option, "
"or change the current working directory to be in a "
"dataset.".format(
getpwd(), " for the purpose {!r}".format(purpose)
if purpose else ''))
dataset = Dataset(dspath)
assert (dataset is not None)
lgr.debug(u"Resolved dataset%s: %s",
u' to {}'.format(purpose) if purpose else '', dataset.path)
if check_installed and not dataset.is_installed():
raise NoDatasetFound(f"No installed dataset found at {dataset.path}")
return dataset
def _flyweight_preproc_path(cls, path):
"""Custom handling for few special abbreviations for datasets"""
path_ = path
if path in ('^', '^.'):
dsroot = get_dataset_root(curdir)
if dsroot is None:
raise NoDatasetFound('No dataset contains path: {}'.format(
str(Path.cwd())))
if path == '^':
# get the topmost dataset from current location. Note that 'zsh'
# might have its ideas on what to do with ^, so better use as -d^
path_ = Dataset(dsroot).get_superdataset(topmost=True).path
elif path == '^.':
# the dataset containing current directory
path_ = dsroot
elif path == '///':
# TODO: logic/UI on installing a default dataset could move here
# from search?
path_ = cfg.obtain('datalad.locations.default-dataset')
if path != path_:
lgr.debug("Resolved dataset alias %r to path %r", path, path_)
return path_