def _get_file_mode(filename, default='copyonwrite'):
"""
Allow file object to already be opened in any of the valid modes and
and leave the file in the same state (opened or closed) as when
the function was called.
"""
mode = default
closed = True
if hasattr(filename, 'closed'):
closed = filename.closed
elif hasattr(filename, 'fileobj') and filename.fileobj is not None:
closed = filename.fileobj.closed
if (isfile(filename) or
isinstance(filename, gzip.GzipFile) and not closed):
if isinstance(filename, gzip.GzipFile):
file_mode = filename.fileobj.mode
else:
file_mode = filename.mode
for key, val in PYTHON_MODES.iteritems():
if val == file_mode:
mode = key
break
return mode, closed
def writeto(self, fileobj, output_verify='exception', clobber=False,
checksum=False):
"""
Write the `HDUList` to a new file.
Parameters
----------
fileobj : file path, file object or file-like object
File to write to. If a file object, must be opened for
append (ab+).
output_verify : str
Output verification option. Must be one of ``"fix"``,
``"silentfix"``, ``"ignore"``, ``"warn"``, or
``"exception"``. See :ref:`verify` for more info.
clobber : bool
When `True`, overwrite the output file if exists.
checksum : bool
When `True` adds both ``DATASUM`` and ``CHECKSUM`` cards
to the headers of all HDU's written to the file.
"""
if (len(self) == 0):
warnings.warn("There is nothing to write.")
return
self.verify(option=output_verify)
# check if the file object is closed
closed = fileobj_closed(fileobj)
fmode = fileobj_mode(fileobj) or 'ab+'
filename = fileobj_name(fileobj)
# check if the output file already exists
if (isfile(fileobj) or
isinstance(fileobj, (basestring, gzip.GzipFile))):
if (os.path.exists(filename) and os.path.getsize(filename) != 0):
if clobber:
warnings.warn("Overwriting existing file '%s'." % filename)
if not closed:
fileobj.close()
os.remove(filename)
else:
raise IOError("File '%s' already exists." % filename)
elif (hasattr(fileobj, 'len') and fileobj.len > 0):
if clobber:
warnings.warn("Overwriting existing file '%s'." % filename)
name.truncate(0)
else:
raise IOError("File '%s' already exists." % filename)
# make sure the EXTEND keyword is there if there is extension
self.update_extend()
mode = 'copyonwrite'
for key, val in PYTHON_MODES.iteritems():
if val == fmode:
mode = key
break
hdulist = fitsopen(fileobj, mode=mode)
for hdu in self:
hdu._prewriteto(checksum=checksum)
try:
hdu._writeto(hdulist.__file)
finally:
hdu._postwriteto()
hdulist.close(output_verify=output_verify, closed=closed)