On 9/6/2010 1:18 PM, tinn...@isbd.co.uk wrote:
I'm using filecmp.cmp() to compare some files (surprise!).
The documentation says:-
Unless shallow is given and is false, files with identical
os.stat() signatures are taken to be equal.
Reword and read carefully: if shallow == True and signatures are
identical, then files are taken to be equal.
Here is the corresponding code from Lib/filecmp.py:
if shallow and s1 == s2:
return True
Does not say the result for non-identical signatures ;-).
I'm not setting shallow explicitly so it's True, thus the function
should be comparing the os.stat() results. However this doesn't seem
to be the case as even if I touch one of the files to change it's
access/modification date filecmp.cmp() still returns True.
Because it goes on to actually compare the files, and they are equal.
...
result = _cache.get((f1, f2))
if result and (s1, s2) == result[:2]:
return result[2]
outcome = _do_cmp(f1, f2)
_cache[f1, f2] = s1, s2, outcome
return outcome
Most of the stdlib files in Python are quite readable. I recommend it
when you have questions.
--
Terry Jan Reedy
--
http://mail.python.org/mailman/listinfo/python-list
