PermissionError WinError32 using CCDData.read on Windows 10

Specs: Astropy 3.0.4, Numpy 1.15.0, Python 3.6.6, conda, Git Bash, Windows 10, MSC v.1900 64 bit (AMD64)

from astropy.nddata import CCDData
filename = 'https://astropy.stsci.edu/data/photometry/spitzer_example_image.fits'
ccd = CCDData.read(filename, numhdu=0)

Downloading https://astropy.stsci.edu/data/photometry/spitzer_example_image.fits
|===========================================| 2.1M/2.1M (100.00%)         2s
---------------------------------------------------------------------------
PermissionError                           Traceback (most recent call last)

~\Miniconda3\envs\py36\lib\site-packages\astropy\nddata\mixins\ndio.py in read(c
ls, *args, **kwargs)
     25         formats.
     26         """
---> 27         return io_registry.read(cls, *args, **kwargs)
     28
     29     def write(self, *args, **kwargs):

~\Miniconda3\envs\py36\lib\site-packages\astropy\io\registry.py in read(cls, for
mat, *args, **kwargs)
    528     finally:
    529         if ctx is not None:
--> 530             ctx.__exit__(*sys.exc_info())
    531
    532     return data

~\Miniconda3\envs\py36\lib\contextlib.py in __exit__(self, type, value, tracebac
k)
     86         if type is None:
     87             try:
---> 88                 next(self.gen)
     89             except StopIteration:
     90                 return False

~\Miniconda3\envs\py36\lib\site-packages\astropy\utils\data.py in get_readable_f
ileobj(name_or_obj, encoding, cache, show_progress, remote_timeout)
    316             fd.close()
    317         for fd in delete_fds:
--> 318             os.remove(fd.name)
    319
    320

PermissionError: [WinError 32] The process cannot access the file because it is
being used by another process: 'C:\\Users\\username\\AppData\\Local\\Temp\\tmp9j3hqa1c'

The weird thing is that I cannot reproduce when calling get_readable_fileobj nor fits.open directly.

@MSeifert04 , since you use Windows too, have you encountered this? Anyone?

[saimn]

Oh that’s because the io.registry downloads the file when it doesn’t know the format, and doesn’t use the cache by default. So using ccd = CCDData.read(filename, numhdu=0, format='fits') goes directly into fits.open which use the cache by default.

[pllim]

Wait, just to clarify… Are you saying that if I use format='fits', then I don’t need to set memmap=False? (I guess there is one way to find out…)