[issue38672] mimetypes.init() fails if no access to one of known files

[R. David Murray]

R. David Murray  added the comment:

I haven't looked at this in detail, but here are my general thoughts: I think 
it would be reasonable to expect that the module would function even if the 
file permissions are screwed up, similar to how unix commands that try to read 
.netrc will (try to) function even if its permissions are wrong.  I would, 
however, expect the module to emit a warning in that case.  I'm of two minds 
about the behavior when the caller specifies filenames explicitly.  I could see 
that going either way, but I lean slightly toward making the behavior 
consistent.  While the programmer might appreciate the traceback, the user of 
the program would probably appreciate the "try to keep going" behavior, since 
the filenames provided will often be in the same class of "standard defaults" 
as the existing well known files are, just in the context of that particular 
application.  But like I said, that is just a lean, and I could go the other 
way on this as well :)

I haven't looked at the isflie issue, but it seems reasonable that if the path 
exists we should make sure it is a file before reading it...but perhaps readfp 
will effectively do that?  Write a test and see what happens :)

I don't know whether to call this change a bug fix or a feature, so I guess 
we'd default to feature unless someone can tilt the balance with an argument :)

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38672] mimetypes.init() fails if no access to one of known files

[Terry J. Reedy]

Terry J. Reedy  added the comment:

An exception report is a failure to finish but not a crash as meant here.

The current code requires all known files and any file explicitly passes to be 
readable.  The proposed simple change would make it OK if none of them are.  
But is this really OK?

Is it really OK if known files are not readable?  Should they not be readable 
by all?

Removing the isfile call would allow directories to be passed through to 
db.readfp.  This might not be a good idea.  We would definitely have to think 
about what errors might be raised on different systems.

I think the try-except should be in init rather than db.read.  The latter can 
be called directly and I think a user explicitly passing an filename should be 
notified.  This comment actually also applies to files passed to init.

[Sidenote: the doc says that MimeTypes "provides an interface similar to the 
one of the mimetypes module."  The mimetypes.db used by mimetypes functions 
*is* a MimeTypes instance and the user can call db methods anything after 
init().]

Overall, I am not convinced that the current behavior is a bug, in which case 
this is an 'enhancement' request that changes the current API.  I am not at all 
a mimetypes expert, so I nosied a couple of email people who have worked on the 
module and should know more.

--
nosy: +maxking, r.david.murray, terry.reedy
title: Crash on mimetypes.init() if there is no access to one of knownfiles -> 
mimetypes.init() fails if no access to one of known files

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com