Source code for bob.io.base

# import Libraries of other lib packages
import numpy
import bob.core

# import our own Library
import bob.extension
bob.extension.load_bob_library('bob.io.base', __file__)

from ._library import File as _File_C, HDF5File as _HDF5File_C, extensions
from . import version
from .version import module as __version__
from .version import api as __api_version__

import os


[docs]class File(_File_C): __doc__ = _File_C.__doc__ def __enter__(self): return self def __exit__(self, type, value, traceback): self.close()
[docs]class HDF5File(_HDF5File_C): __doc__ = _HDF5File_C.__doc__ def __enter__(self): return self def __exit__(self, type, value, traceback): return self.close() def __contains__(self, x): __doc__ = self.has_key.__doc__ return self.has_key(x) def __iter__(self): __doc__ = self.keys.__doc__ return iter(self.keys()) def __getitem__(self, name): __doc__ = self.get.__doc__ return self.get(name) def __setitem__(self, name, value): __doc__ = self.set.__doc__ return self.set(name, value)
[docs] def values(self): '''Yields the datasets contained in the current directory. Yields ------- object The datasets that are being read. ''' return (self[key] for key in self)
[docs] def items(self): '''Yields the keys and the datasets contained in the current directory. Yields ------- tuple The key and the datasets that are being read in a tuple. ''' return ((key, self[key]) for key in self)
def _is_string(s): """Returns ``True`` if the given object is a string This method can be used with Python-2.x or 3.x and returns a string respecting each environment's constraints. """ from sys import version_info return (version_info[0] < 3 and isinstance(s, (str, unicode))) or \ isinstance(s, (bytes, str))
[docs]def create_directories_safe(directory, dryrun=False): """Creates a directory if it does not exists, with concurrent access support. This function will also create any parent directories that might be required. If the dryrun option is selected, it does not actually create the directory, but just writes the (Linux) command that would have been executed. **Parameters:** ``directory`` : str The directory that you want to create. ``dryrun`` : bool Only ``print`` the command to console, but do not execute it. """ try: if dryrun: print("[dry-run] mkdir -p '%s'" % directory) else: if directory and not os.path.exists(directory): os.makedirs(directory) except OSError as exc: # Python >2.5 import errno if exc.errno != errno.EEXIST: raise
[docs]def load(inputs): """load(inputs) -> data Loads the contents of a file, an iterable of files, or an iterable of :py:class:`bob.io.base.File`'s into a :py:class:`numpy.ndarray`. **Parameters:** ``inputs`` : various types This might represent several different entities: 1. The name of a file (full path) from where to load the data. In this case, this assumes that the file contains an array and returns a loaded numpy ndarray. 2. An iterable of filenames to be loaded in memory. In this case, this would assume that each file contains a single 1D sample or a set of 1D samples, load them in memory and concatenate them into a single and returned 2D :py:class:`numpy.ndarray`. 3. An iterable of :py:class:`File`. In this case, this would assume that each :py:class:`File` contains a single 1D sample or a set of 1D samples, load them in memory if required and concatenate them into a single and returned 2D :py:class:`numpy.ndarray`. 4. An iterable with mixed filenames and :py:class:`File`. In this case, this would returned a 2D :py:class:`numpy.ndarray`, as described by points 2 and 3 above. **Returns:** ``data`` : :py:class:`numpy.ndarray` The data loaded from the given ``inputs``. """ from collections import Iterable import numpy if _is_string(inputs): return File(inputs, 'r').read() elif isinstance(inputs, Iterable): retval = [] for obj in inputs: if _is_string(obj): retval.append(load(obj)) elif isinstance(obj, File): retval.append(obj.read()) else: raise TypeError( "Iterable contains an object which is not a filename nor a " "bob.io.base.File.") return numpy.vstack(retval) else: raise TypeError( "Unexpected input object. This function is expecting a filename, " "or an iterable of filenames and/or bob.io.base.File's")
[docs]def merge(filenames): """merge(filenames) -> files Converts an iterable of filenames into an iterable over read-only :py:class:`bob.io.base.File`'s. **Parameters:** ``filenames`` : str or [str] A list of file names. This might represent: 1. A single filename. In this case, an iterable with a single :py:class:`File` is returned. 2. An iterable of filenames to be converted into an iterable of :py:class:`File`'s. **Returns:** ``files`` : [:py:class:`File`] The list of files. """ from collections import Iterable from .utils import is_string if is_string(filenames): return [File(filenames, 'r')] elif isinstance(filenames, Iterable): return [File(k, 'r') for k in filenames] else: raise TypeError( "Unexpected input object. This function is expecting an " "iterable of filenames.")
[docs]def save(array, filename, create_directories=False): """Saves the contents of an array-like object to file. Effectively, this is the same as creating a :py:class:`File` object with the mode flag set to ``'w'`` (write with truncation) and calling :py:meth:`File.write` passing ``array`` as parameter. Parameters: ``array`` : array_like The array-like object to be saved on the file ``filename`` : str The name of the file where you need the contents saved to ``create_directories`` : bool Automatically generate the directories if required (defaults to ``False`` because of compatibility reasons; might change in future to default to ``True``) """ # create directory if not existent yet if create_directories: create_directories_safe(os.path.dirname(filename)) # requires data is c-contiguous and aligned, will create a copy otherwise array = numpy.require(array, requirements=('C_CONTIGUOUS', 'ALIGNED')) return File(filename, 'w').write(array)
# Just to make it homogenous with the C++ API write = save read = load
[docs]def append(array, filename): """append(array, filename) -> position Appends the contents of an array-like object to file. Effectively, this is the same as creating a :py:class:`File` object with the mode flag set to ``'a'`` (append) and calling :py:meth:`File.append` passing ``array`` as parameter. **Parameters:** ``array`` : array_like The array-like object to be saved on the file ``filename`` : str The name of the file where you need the contents saved to **Returns:** ``position`` : int See :py:meth:`File.append` """ # requires data is c-contiguous and aligned, will create a copy otherwise array = numpy.require(array, requirements=('C_CONTIGUOUS', 'ALIGNED')) return File(filename, 'a').append(array)
[docs]def peek(filename): """peek(filename) -> dtype, shape, stride Returns the type of array (frame or sample) saved in the given file. Effectively, this is the same as creating a :py:class:`File` object with the mode flag set to `r` (read-only) and calling :py:meth:`File.describe`. **Parameters**: ``filename`` : str The name of the file to peek information from **Returns:** ``dtype, shape, stride`` : see :py:meth:`File.describe` """ return File(filename, 'r').describe()
[docs]def peek_all(filename): """peek_all(filename) -> dtype, shape, stride Returns the type of array (for full readouts) saved in the given file. Effectively, this is the same as creating a :py:class:`File` object with the mode flag set to ``'r'`` (read-only) and returning ``File.describe`` with its parameter ``all`` set to ``True``. **Parameters:** ``filename`` : str The name of the file to peek information from **Returns:** ``dtype, shape, stride`` : see :py:meth:`File.describe` """ return File(filename, 'r').describe(all=True)
# Keeps compatibility with the previously existing API open = File
[docs]def get_config(): """Returns a string containing the configuration information. """ return bob.extension.get_config(__name__, version.externals, version.api)
[docs]def get_include_directories(): """get_include_directories() -> includes Returns a list of include directories for dependent libraries, such as HDF5. This function is automatically used by :py:func:`bob.extension.get_bob_libraries` to retrieve the non-standard include directories that are required to use the C bindings of this library in dependent classes. You shouldn't normally need to call this function by hand. **Returns:** ``includes`` : [str] The list of non-standard include directories required to use the C bindings of this class. For now, only the directory for the HDF5 headers are returned. """ # try to use pkg_config first try: from bob.extension.utils import find_header # locate pkg-config on our own header = 'hdf5.h' candidates = find_header(header) if not candidates: raise RuntimeError( "could not find %s's `%s' - have you installed %s on this " "machine?" % ('hdf5', header, 'hdf5')) return [os.path.dirname(candidates[0])] except RuntimeError: from bob.extension import pkgconfig pkg = pkgconfig('hdf5') return pkg.include_directories()
[docs]def get_macros(): """get_macros() -> macros Returns a list of preprocessor macros, such as ``(HAVE_HDF5, 1)``. This function is automatically used by :py:func:`bob.extension.get_bob_libraries` to retrieve the prerpocessor definitions that are required to use the C bindings of this library in dependent classes. You shouldn't normally need to call this function by hand. **Returns:** ``macros`` : [(str,str)] The list of preprocessor macros required to use the C bindings of this class. For now, only ``('HAVE_HDF5', '1')`` is returned, when applicable. """ # get include directories if get_include_directories(): return [('HAVE_HDF5', '1')]
# gets sphinx autodoc done right - don't remove it __all__ = [_ for _ in dir() if not _.startswith('_')]