fitsGeneric.py

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# This file is part of obs_base.
#
# Developed for the LSST Data Management System.
# This product includes software developed by the LSST Project
# (http://www.lsst.org).
# See the COPYRIGHT file at the top-level directory of this distribution
# for details of code ownership.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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__all__ = ("FitsGenericFormatter", )
 
import os.path
 
from lsst.daf.butler.formatters.file import FileFormatter
 
 
class FitsGenericFormatter(FileFormatter):
    """Interface for reading and writing objects that support the standard
    afw I/O readFits/writeFits methods.
    """
    supportedExtensions = frozenset({".fits", ".fits.gz", ".fits.fz", ".fz", ".fit"})
    extension = ".fits"
 
    def _readFile(self, path, pytype):
        """Read a file from the path in FITS format.
 
        Parameters
        ----------
        path : `str`
            Path to use to open the file.
        pytype : `class`
            Class to use to read the FITS file.
 
        Returns
        -------
        data : `object`
            Instance of class `pytype` read from FITS file. None
            if the file could not be opened.
        """
        if not os.path.exists(path):
            return None
 
        return pytype.readFits(path)
 
    def _writeFile(self, inMemoryDataset):
        """Write the in memory dataset to file on disk.
 
        Parameters
        ----------
        inMemoryDataset : `object`
            Object to serialize.
 
        Raises
        ------
        Exception
            The file could not be written.
        """
        inMemoryDataset.writeFits(self.fileDescriptor.location.path)