(Possible) Issues in the tutorial notebook

[karenkathryn]

RE: iraf_specreduce_tutorial.ipynb
While looking at this tutorial, I came across a few issues in the following code:

Block 3:

import ccdproc 
from ccdproc import CCDData, ImageFileCollection

and
Block 4:

from ccdproc import ImageFileCollection
image_dir = 'exercises/spec/'
ic = ImageFileCollection('exercises/spec/') #read in all FITS files in the directory

Issues:

1. from ccdproc import CCDData, ImageFileCollection and from ccdproc import ImageFileCollection should be covered by import ccdproc
2. In block 4, ImageFileCollection is already imported in block 3
3. ImageFileCollection('exercises/spec/') should be able to be replaced with ImageFileCollection(image_dir)
   Finally-
4. In the introduction, the link to 'some data' results in a 404 error.

[crawfordsm]

Thanks for the feedback @karenkathryn ! I haven't been able to keep this up to date, but I'll try to make the updates and make sure that the data are available. Please let me know if there is any other help I can provide!