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Author tkruse
Recipients tkruse
Date 2018-09-11.16:36:08
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <1536683769.28.0.0269046726804.issue34629@psf.upfronthosting.co.za>
In-reply-to
Content
We had a problem running code that downloads files from github when porting from python2.7 to python3.[3-7]. Not sure if a bug or not.

With the given code, in python3 a file downloaded in chunks will contain the size of chunks when using the undocumented fp from urlopen(...).fp. In python2, only the chunk payload would make it into the file.

We assume that we can just use the urlopen response directly as a fix (without '.fp'), but though it might still be nice to report the difference.

Short code:
resp = urlopen('http://someurl')
fhand = os.fdopen(fdesc, "wb")
shutil.copyfileobj(resp.fp, fhand)   # using .fp here is the dodgy part
fhand.close()

The attached script demonstrates the difference:

$ python --version
Python 2.7.15rc1
$ python urllib_issue.py 
127.0.0.1 - - [12/Sep/2018 01:27:28] "GET /downloads/1.0.tar.gz HTTP/1.1" 200 -

$ python3 --version
Python 3.6.5
$ python3 urllib_issue.py 
127.0.0.1 - - [12/Sep/2018 01:27:37] "GET /downloads/1.0.tar.gz HTTP/1.1" 200 -
Traceback (most recent call last):
  File "urllib_issue.py", line 87, in <module>
    assert data == FILE_CONTENT, '%s, %s'%(len(FILE_CONTENT), len(data))
AssertionError: 100000, 100493
!!! BASH reports ERROR: shell returned 1
History
Date User Action Args
2018-09-11 16:36:09tkrusesetrecipients: + tkruse
2018-09-11 16:36:09tkrusesetmessageid: <1536683769.28.0.0269046726804.issue34629@psf.upfronthosting.co.za>
2018-09-11 16:36:09tkruselinkissue34629 messages
2018-09-11 16:36:09tkrusecreate