`astropy.io.fits.diff:HeaderDiff`

source: /astropy/io/fits/diff.py :657

Signature

   class     HeaderDiff (    a    ,    b    ,    ignore_keywords    =  []   ,    ignore_comments    =  []   ,    rtol    =  0.0   ,    atol    =  0.0   ,    ignore_blanks    =  True   ,    ignore_blank_cards    =  True     )

Members

Summary

Diff two Header objects.

Extended Summary

HeaderDiff objects have the following diff attributes:

diff_keyword_count: If the two headers contain a different number of keywords, this contains a 2-tuple of the keyword count for each header.
diff_keywords: If either header contains one or more keywords that don't appear at all in the other header, this contains a 2-tuple consisting of a list of the keywords only appearing in header a, and a list of the keywords only appearing in header b.
diff_duplicate_keywords: If a keyword appears in both headers at least once, but contains a different number of duplicates (for example, a different number of HISTORY cards in each header), an item is added to this dict with the keyword as the key, and a 2-tuple of the different counts of that keyword as the value. For example
```
{'HISTORY': (20, 19)}
```
means that header a contains 20 HISTORY cards, while header b contains only 19 HISTORY cards.
diff_keyword_values: If any of the common keyword between the two headers have different values, they appear in this dict. It has a structure similar to diff_duplicate_keywords, with the keyword as the key, and a 2-tuple of the different values as the value. For example
```
{'NAXIS': (2, 3)}
```
means that the NAXIS keyword has a value of 2 in header a, and a value of 3 in header b. This excludes any keywords matched by the ignore_keywords list.
diff_keyword_comments: Like diff_keyword_values, but contains differences between keyword comments.

HeaderDiff objects also have a common_keywords attribute that lists all keywords that appear in both headers.

Aliases

astropy.io.fits.HeaderDiff