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Unnecessary import of astropy.table can slow down load of a FITS file

See original GitHub issue

I am doing a little bit of io.fits benchmarking and one thing I just noticed is this import of astropy.table can take a significant fraction of the load time of a FITS file even in cases where it isn’t needed at all.

The easiest optimisation would be to only try the table import if data is not None but someone with a little more imagination might be able to optimise further.

My truncated pyinstrument trace:

0.488 <module>  initial_benchmarks_astropy.py:1
├─ 0.207 HDUList.__getitem__  ../../../Git/astropy/astropy/io/fits/hdu/hdulist.py:304
│  └─ 0.207 HDUList._try_while_unread_hdus  ../../../Git/astropy/astropy/io/fits/hdu/hdulist.py:1171
│     └─ 0.207 HDUList._read_next_hdu  ../../../Git/astropy/astropy/io/fits/hdu/hdulist.py:1188
│        └─ 0.207 _BaseHDU.readfrom  ../../../Git/astropy/astropy/io/fits/hdu/base.py:299
│           └─ 0.207 CompImageHDU._readfrom_internal  ../../../Git/astropy/astropy/io/fits/hdu/base.py:382
│              └─ 0.206 CompImageHDU.__init__  ../../../Git/astropy/astropy/io/fits/hdu/compressed.py:403
│                 └─ 0.206 CompImageHDU.__init__  ../../../Git/astropy/astropy/io/fits/hdu/table.py:851
│                    └─ 0.206 <module>  ../../../Git/astropy/astropy/table/__init__.py:1

Issue Analytics

State:
Created 10 months ago
Comments:5 (5 by maintainers)

Top GitHub Comments

2reactions

pllimcommented, Nov 21, 2022

Never put a FITS issue as “good first issue.” 😉

1reaction

saimncommented, Nov 22, 2022

Let’s try with “good first issue” then 😃

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