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Title: inspect.getsource doesn't update when a module is reloaded
Type: behavior Stage: resolved
Components: Library (Lib) Versions: Python 3.4, Python 3.5, Python 2.7
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: Nosy List: ajaksu2, berker.peksag, georg.brandl, gpolo, jaraco, python-dev, r.david.murray, sonderblade, yselivanov
Priority: normal Keywords: patch

Created on 2005-06-10 13:49 by sonderblade, last changed 2022-04-11 14:56 by admin. This issue is now closed.

File name Uploaded Description Edit gpolo, 2008-02-07 19:42 review
test_inspect-trunk.diff ajaksu2, 2009-04-25 19:38 Test source reloading with inspect.getsource review
test_inspect-py3k2.diff ajaksu2, 2009-04-25 20:08 Test source reloading with inspect.getsource in py3k review
issue1218234.diff berker.peksag, 2012-12-10 08:00 review
Messages (16)
msg60756 - (view) Author: Björn Lindqvist (sonderblade) Date: 2005-06-10 13:49
This is

def foo():
    print "Bla"

And in an interactive session:

>>> import inspect, test
>>> inspect.getsource(
'def foo():\n    print "Bla"\n'

Now I edit to (without exiting the interactive

def foo():
    print "Oh no!"

>>> reload(test)
<module 'test' from ''>
Oh no!
>>> inspect.getsource(
'def foo():\n    print "Bla"\n'

inspect should output the new source.
msg60757 - (view) Author: Georg Brandl (georg.brandl) * (Python committer) Date: 2005-06-10 16:36
Logged In: YES 

This is the fault of the linecache module which inspect
uses. It caches the file contents and does not reload it
accordingly. However, I assume it's pretty hard finding a
good solution to this.
msg62174 - (view) Author: Guilherme Polo (gpolo) * (Python committer) Date: 2008-02-07 19:42
I'm attaching a patch. Is there some hidden problem that it may cause ?
By the way, this issue is a duplicate of
msg86540 - (view) Author: Daniel Diniz (ajaksu2) * (Python triager) Date: 2009-04-25 19:38
Fix was committed to py3k but with no tests AFAIK. Here's a (failing)
test for trunk that runs OK after Guilherme's patch.

We might want to keep this behavior restricted for when the module was
msg86544 - (view) Author: Daniel Diniz (ajaksu2) * (Python triager) Date: 2009-04-25 20:08
Er, no, it wasn't committed to py3k, it was just me getting my patches
mixed. Attaching the py3k test with relative import fixed.
msg110435 - (view) Author: Mark Lawrence (BreamoreBoy) * Date: 2010-07-16 13:23
The change to is two lines.  Given that unit test patches are also supplied could someone with the knowledge give yes or no to accepting this patch?
msg110436 - (view) Author: Jean-Paul Calderone (exarkun) * (Python committer) Date: 2010-07-16 13:27
Calling linecache.checkcache for every inspect.getsource call sounds like a fairly bad idea to me.

linecache.checkcache does a stat() of every single cached file.
msg110438 - (view) Author: Jean-Paul Calderone (exarkun) * (Python committer) Date: 2010-07-16 13:31
> linecache.checkcache does a stat() of every single cached file.

Ah, sorry.  I didn't read carefully enough.  I see that the patch passes in the filename and checkcache restricts the work it does in that case.

Something else to consider, though, is that this change means you'll also get the new source if you *don't* reload the module, too.  So, what exactly is inspect.getsource() supposed to be doing?  Giving you the current on-disk contents of the relevant source file?  Or giving you the actual source corresponding to the object passed to it?

If the latter, then this actually needs to be more tightly integrated with module reloading somehow.
msg217951 - (view) Author: Jason R. Coombs (jaraco) * (Python committer) Date: 2014-05-05 20:18
This issue appears implicated in
msg217990 - (view) Author: Yury Selivanov (yselivanov) * (Python committer) Date: 2014-05-06 15:33
Thanks, I'll take a look at the patch.
msg217991 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2014-05-06 15:57
Note that there has never been a strict correspondence between linecache/getsource, the module in memory, and the code on disk.  If the file is changed before a traceback is generated, for example, you will get the new source.  That doesn't mean fixing the reload case is wrong, it's just something to keep in mind.
msg232328 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2014-12-08 21:06
New changeset 8e2505d535c8 by Yury Selivanov in branch 'default':
inspect: Fix getsource() to load updated source of reloaded module
msg232329 - (view) Author: Yury Selivanov (yselivanov) * (Python committer) Date: 2014-12-08 21:07
Fixed in 3.5. Not sure if we need to backport this to 3.4 and 2.7.

Closing this issue. Thanks to Björn Lindqvist and Berker Peksag!
msg232332 - (view) Author: Jason R. Coombs (jaraco) * (Python committer) Date: 2014-12-08 21:48
FWIW, I'd appreciate a backport to 3.4, given that 3.5 is scheduled for release in Sep 2015.
msg232335 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2014-12-08 23:01
New changeset e52d8e888df1 by Yury Selivanov in branch '3.4':
inspect: Fix getsource() to load updated source of reloaded module
msg232336 - (view) Author: Yury Selivanov (yselivanov) * (Python committer) Date: 2014-12-08 23:10
@Jason: done ;)
Date User Action Args
2022-04-11 14:56:11adminsetgithub: 42071
2014-12-08 23:10:15yselivanovsetmessages: + msg232336
2014-12-08 23:01:53python-devsetmessages: + msg232335
2014-12-08 22:24:35berker.peksagsetstage: patch review -> resolved
2014-12-08 21:48:50jaracosetmessages: + msg232332
2014-12-08 21:07:36yselivanovsetstatus: open -> closed
resolution: fixed
2014-12-08 21:07:29yselivanovsetmessages: + msg232329
2014-12-08 21:06:18python-devsetnosy: + python-dev
messages: + msg232328
2014-05-06 15:57:13r.david.murraysetnosy: + r.david.murray
messages: + msg217991
2014-05-06 15:33:58yselivanovsetmessages: + msg217990
2014-05-06 05:54:48berker.peksagsetnosy: + yselivanov

versions: + Python 3.5, - Python 3.2, Python 3.3
2014-05-05 23:41:59exarkunsetnosy: - exarkun
2014-05-05 20:18:07jaracosetnosy: + jaraco
messages: + msg217951
2014-02-03 19:05:36BreamoreBoysetnosy: - BreamoreBoy
2012-12-10 08:01:48berker.peksagsetnosy: + berker.peksag
2012-12-10 08:00:46berker.peksagsetfiles: + issue1218234.diff
versions: + Python 3.3, Python 3.4, - Python 3.1
2010-07-16 13:31:59exarkunsetmessages: + msg110438
2010-07-16 13:27:42exarkunsetnosy: + exarkun
messages: + msg110436
2010-07-16 13:23:06BreamoreBoysetnosy: + BreamoreBoy

messages: + msg110435
versions: + Python 3.1, Python 2.7, Python 3.2, - Python 2.6, Python 3.0
2009-04-25 20:08:18ajaksu2setfiles: - test_inspect-py3k.diff
2009-04-25 20:08:09ajaksu2setfiles: + test_inspect-py3k2.diff

messages: + msg86544
2009-04-25 19:39:15ajaksu2setfiles: + test_inspect-py3k.diff
2009-04-25 19:38:32ajaksu2setfiles: + test_inspect-trunk.diff

type: behavior
versions: + Python 2.6, Python 3.0, - Python 2.5
keywords: + patch
nosy: + ajaksu2

messages: + msg86540
stage: patch review
2009-04-05 18:16:38georg.brandllinkissue993580 superseder
2009-04-05 18:16:38georg.brandlunlinkissue993580 dependencies
2009-03-04 15:13:21ajaksu2linkissue993580 dependencies
2008-02-07 19:42:24gpolosetfiles: +
nosy: + gpolo
messages: + msg62174
2005-06-10 13:49:10sonderbladecreate