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Class: HdfLoader

HDF Loader contains the filename and hdfmap for a HDF file, the hdfmap contains all the dataset paths and a namespace, allowing data to be called from the file using variable names, loading only the required datasets for each operation.

E.G.

hdf = HdfLoader('file.hdf')
[data1, data2] = hdf.get_data(*['dataset_name_1', 'dataset_name_2'])
data = hdf.eval('dataset_name_1 * 100 + 2')
string = hdf.format('my data is {dataset_name_1:.2f}')
print(hdf.summary())
Source code in src/hdfmap/reloader_class.py 
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class HdfLoader:
    """
    HDF Loader contains the filename and hdfmap for a HDF file, the hdfmap contains all the dataset paths and a
    namespace, allowing data to be called from the file using variable names, loading only the required datasets
    for each operation.

    ### E.G.
        hdf = HdfLoader('file.hdf')
        [data1, data2] = hdf.get_data(*['dataset_name_1', 'dataset_name_2'])
        data = hdf.eval('dataset_name_1 * 100 + 2')
        string = hdf.format('my data is {dataset_name_1:.2f}')
        print(hdf.summary())
    """

    def __init__(self, hdf_filename: str, hdf_map: HdfMap | NexusMap | None = None):
        self.filename = hdf_filename
        if hdf_map is None:
            self.map = create_hdf_map(hdf_filename)
        else:
            self.map = hdf_map

    def __repr__(self):
        return f"HdfReloader('{self.filename}')"

    def __str__(self):
        with self._load() as hdf:
            out = self.map.info_data(hdf)
        return out

    def __getitem__(self, item):
        return self.get_data(item)

    def __call__(self, expression):
        return self.eval(expression)

    def _load(self) -> h5py.File:
        return load_hdf(self.filename)

    def get_hdf_path(self, name_or_path: str) -> str or None:
        """Return hdf path of object in HdfMap"""
        return self.map.get_path(name_or_path)

    def find_hdf_paths(self, string: str, name_only: bool = True, whole_word: bool = False) -> list[str]:
        """
        Find any dataset paths that contain the given string argument
        :param string: str to find in list of datasets
        :param name_only: if True, search only the name of the dataset, not the full path
        :param whole_word: if True, search only for case in-sensitive name
        :return: list of hdf paths
        """
        return self.map.find_paths(string, name_only, whole_word)

    def find_names(self, string: str) -> list[str]:
        """
        Find any dataset names that contain the given string argument, searching names in self.combined
        :param string: str to find in list of datasets
        :return: list of names
        """
        return self.map.find_names(string)

    def get_data(self, *name_or_path, index: slice = (), default=None, direct_load=False):
        """
        Return data from dataset in file, converted into either datetime, str or squeezed numpy.array objects
        See hdfmap.eval_functions.dataset2data for more information.
        :param name_or_path: str name or path pointing to dataset in hdf file
        :param index: index or slice of data in hdf file
        :param default: value to return if name not found in hdf file
        :param direct_load: return str, datetime or squeezed array if False, otherwise load data directly
        :return: dataset2data(dataset) -> datetime, str or squeezed array as required.
        """
        with self._load() as hdf:
            out = [self.map.get_data(hdf, name, index, default, direct_load) for name in name_or_path]
        if len(name_or_path) == 1:
            return out[0]
        return out

    def get_string(self, *name_or_path, index: slice = (), default='', units=False):
        """
        Return data from dataset in file, converted into summary string
        See hdfmap.eval_functions.dataset2data for more information.
        :param name_or_path: str name or path pointing to dataset in hdf file
        :param index: index or slice of data in hdf file
        :param default: value to return if name not found in hdf file
        :param units: if True and attribute 'units' available, append this to the result
        :return: dataset2str(dataset) -> str
        """
        with self._load() as hdf:
            out = [self.map.get_string(hdf, name, index, default, units) for name in name_or_path]
        if len(name_or_path) == 1:
            return out[0]
        return out

    def get_image(self, index: slice = None) -> np.ndarray:
        """
        Get image data from file, using default image path
        :param index: (slice,) or None to take the middle image
        :return: numpy array of image
        """
        with self._load() as hdf:
            return self.map.get_image(hdf, index)

    def get_metadata(self, defaults=None):
        with self._load() as hdf:
            return self.map.get_metadata(hdf, default=defaults)

    def get_scannables(self):
        """Return scannables from file (values associated with hdfmap.scannables)"""
        with self._load() as hdf:
            return self.map.get_scannables(hdf)

    def summary(self) -> str:
        """Return string summary of datasets"""
        with self._load() as hdf:
            return self.map.create_dataset_summary(hdf)

    def eval(self, expression: str, default=DEFAULT):
        """
        Evaluate an expression using the namespace of the hdf file
        :param expression: str expression to be evaluated
        :param default: returned if varname not in namespace
        :return: eval(expression)
        """
        with self._load() as hdf:
            return self.map.eval(hdf, expression, default)

    def format(self, expression: str, default=DEFAULT):
        """
        Evaluate a formatted string expression using the namespace of the hdf file
        :param expression: str expression using {name} format specifiers
        :param default: returned if varname not in namespace
        :return: eval_hdf(f"expression")
        """
        with self._load() as hdf:
            return self.map.format_hdf(hdf, expression, default)

eval(expression, default=DEFAULT)

Evaluate an expression using the namespace of the hdf file

Parameters:

Name Type Description Default
expression str

str expression to be evaluated

 required
default

returned if varname not in namespace

 DEFAULT

Returns:

Type Description

eval(expression)
Source code in src/hdfmap/reloader_class.py 
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def eval(self, expression: str, default=DEFAULT):
    """
    Evaluate an expression using the namespace of the hdf file
    :param expression: str expression to be evaluated
    :param default: returned if varname not in namespace
    :return: eval(expression)
    """
    with self._load() as hdf:
        return self.map.eval(hdf, expression, default)

find_hdf_paths(string, name_only=True, whole_word=False)

Find any dataset paths that contain the given string argument

Parameters:

Name Type Description Default
string str

str to find in list of datasets

 required
name_only bool

if True, search only the name of the dataset, not the full path

 True
whole_word bool

if True, search only for case in-sensitive name

 False

Returns:

Type Description
list[str]

list of hdf paths
Source code in src/hdfmap/reloader_class.py 
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def find_hdf_paths(self, string: str, name_only: bool = True, whole_word: bool = False) -> list[str]:
    """
    Find any dataset paths that contain the given string argument
    :param string: str to find in list of datasets
    :param name_only: if True, search only the name of the dataset, not the full path
    :param whole_word: if True, search only for case in-sensitive name
    :return: list of hdf paths
    """
    return self.map.find_paths(string, name_only, whole_word)

find_names(string)

Find any dataset names that contain the given string argument, searching names in self.combined

Parameters:

Name Type Description Default
string str

str to find in list of datasets

 required

Returns:

Type Description
list[str]

list of names
Source code in src/hdfmap/reloader_class.py 
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def find_names(self, string: str) -> list[str]:
    """
    Find any dataset names that contain the given string argument, searching names in self.combined
    :param string: str to find in list of datasets
    :return: list of names
    """
    return self.map.find_names(string)

format(expression, default=DEFAULT)

Evaluate a formatted string expression using the namespace of the hdf file

Parameters:

Name Type Description Default
expression str

str expression using {name} format specifiers

 required
default

returned if varname not in namespace

 DEFAULT

Returns:

Type Description

eval_hdf(f"expression")
Source code in src/hdfmap/reloader_class.py 
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def format(self, expression: str, default=DEFAULT):
    """
    Evaluate a formatted string expression using the namespace of the hdf file
    :param expression: str expression using {name} format specifiers
    :param default: returned if varname not in namespace
    :return: eval_hdf(f"expression")
    """
    with self._load() as hdf:
        return self.map.format_hdf(hdf, expression, default)

get_data(*name_or_path, index=(), default=None, direct_load=False)

Return data from dataset in file, converted into either datetime, str or squeezed numpy.array objects See hdfmap.eval_functions.dataset2data for more information.

Parameters:

Name Type Description Default
name_or_path

str name or path pointing to dataset in hdf file

 ()
index slice

index or slice of data in hdf file

 ()
default

value to return if name not found in hdf file

 None
direct_load

return str, datetime or squeezed array if False, otherwise load data directly

 False

Returns:

Type Description

dataset2data(dataset) -> datetime, str or squeezed array as required.
Source code in src/hdfmap/reloader_class.py 
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def get_data(self, *name_or_path, index: slice = (), default=None, direct_load=False):
    """
    Return data from dataset in file, converted into either datetime, str or squeezed numpy.array objects
    See hdfmap.eval_functions.dataset2data for more information.
    :param name_or_path: str name or path pointing to dataset in hdf file
    :param index: index or slice of data in hdf file
    :param default: value to return if name not found in hdf file
    :param direct_load: return str, datetime or squeezed array if False, otherwise load data directly
    :return: dataset2data(dataset) -> datetime, str or squeezed array as required.
    """
    with self._load() as hdf:
        out = [self.map.get_data(hdf, name, index, default, direct_load) for name in name_or_path]
    if len(name_or_path) == 1:
        return out[0]
    return out

get_hdf_path(name_or_path)

Return hdf path of object in HdfMap

Source code in src/hdfmap/reloader_class.py 
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def get_hdf_path(self, name_or_path: str) -> str or None:
    """Return hdf path of object in HdfMap"""
    return self.map.get_path(name_or_path)

get_image(index=None)

Get image data from file, using default image path

Parameters:

Name Type Description Default
index slice

(slice,) or None to take the middle image

 None

Returns:

Type Description
ndarray

numpy array of image
Source code in src/hdfmap/reloader_class.py 
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def get_image(self, index: slice = None) -> np.ndarray:
    """
    Get image data from file, using default image path
    :param index: (slice,) or None to take the middle image
    :return: numpy array of image
    """
    with self._load() as hdf:
        return self.map.get_image(hdf, index)

get_scannables()

Return scannables from file (values associated with hdfmap.scannables)

Source code in src/hdfmap/reloader_class.py 
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def get_scannables(self):
    """Return scannables from file (values associated with hdfmap.scannables)"""
    with self._load() as hdf:
        return self.map.get_scannables(hdf)

get_string(*name_or_path, index=(), default='', units=False)

Return data from dataset in file, converted into summary string See hdfmap.eval_functions.dataset2data for more information.

Parameters:

Name Type Description Default
name_or_path

str name or path pointing to dataset in hdf file

 ()
index slice

index or slice of data in hdf file

 ()
default

value to return if name not found in hdf file

 ''
units

if True and attribute 'units' available, append this to the result

 False

Returns:

Type Description

dataset2str(dataset) -> str
Source code in src/hdfmap/reloader_class.py 
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def get_string(self, *name_or_path, index: slice = (), default='', units=False):
    """
    Return data from dataset in file, converted into summary string
    See hdfmap.eval_functions.dataset2data for more information.
    :param name_or_path: str name or path pointing to dataset in hdf file
    :param index: index or slice of data in hdf file
    :param default: value to return if name not found in hdf file
    :param units: if True and attribute 'units' available, append this to the result
    :return: dataset2str(dataset) -> str
    """
    with self._load() as hdf:
        out = [self.map.get_string(hdf, name, index, default, units) for name in name_or_path]
    if len(name_or_path) == 1:
        return out[0]
    return out

summary()

Return string summary of datasets

Source code in src/hdfmap/reloader_class.py 
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def summary(self) -> str:
    """Return string summary of datasets"""
    with self._load() as hdf:
        return self.map.create_dataset_summary(hdf)