Spaces:
Running
Running
| # This file is part of h5py, a Python interface to the HDF5 library. | |
| # | |
| # http://www.h5py.org | |
| # | |
| # Copyright 2008-2013 Andrew Collette and contributors | |
| # | |
| # License: Standard 3-clause BSD; see "license.txt" for full license terms | |
| # and contributor agreement. | |
| """ | |
| Implements a portion of the selection operations. | |
| """ | |
| import numpy as np | |
| from .. import h5s | |
| def read_dtypes(dataset_dtype, names): | |
| """ Returns a 2-tuple containing: | |
| 1. Output dataset dtype | |
| 2. Dtype containing HDF5-appropriate description of destination | |
| """ | |
| if len(names) == 0: # Not compound, or all fields needed | |
| format_dtype = dataset_dtype | |
| elif dataset_dtype.names is None: | |
| raise ValueError("Field names only allowed for compound types") | |
| elif any(x not in dataset_dtype.names for x in names): | |
| raise ValueError("Field does not appear in this type.") | |
| else: | |
| format_dtype = np.dtype([(name, dataset_dtype.fields[name][0]) for name in names]) | |
| if len(names) == 1: | |
| # We don't preserve the field information if only one explicitly selected. | |
| output_dtype = format_dtype.fields[names[0]][0] | |
| else: | |
| output_dtype = format_dtype | |
| return output_dtype, format_dtype | |
| def read_selections_scalar(dsid, args): | |
| """ Returns a 2-tuple containing: | |
| 1. Output dataset shape | |
| 2. HDF5 dataspace containing source selection. | |
| Works for scalar datasets. | |
| """ | |
| if dsid.shape != (): | |
| raise RuntimeError("Illegal selection function for non-scalar dataset") | |
| if args == (): | |
| # This is a signal that an array scalar should be returned instead | |
| # of an ndarray with shape () | |
| out_shape = None | |
| elif args == (Ellipsis,): | |
| out_shape = () | |
| else: | |
| raise ValueError("Illegal slicing argument for scalar dataspace") | |
| source_space = dsid.get_space() | |
| source_space.select_all() | |
| return out_shape, source_space | |
| class ScalarReadSelection: | |
| """ | |
| Implements slicing for scalar datasets. | |
| """ | |
| def __init__(self, fspace, args): | |
| if args == (): | |
| self.mshape = None | |
| elif args == (Ellipsis,): | |
| self.mshape = () | |
| else: | |
| raise ValueError("Illegal slicing argument for scalar dataspace") | |
| self.mspace = h5s.create(h5s.SCALAR) | |
| self.fspace = fspace | |
| def __iter__(self): | |
| self.mspace.select_all() | |
| yield self.fspace, self.mspace | |
| def select_read(fspace, args): | |
| """ Top-level dispatch function for reading. | |
| At the moment, only supports reading from scalar datasets. | |
| """ | |
| if fspace.shape == (): | |
| return ScalarReadSelection(fspace, args) | |
| raise NotImplementedError() | |