urlparse example is wrong

[abalkin]

BPO	10226
Nosy	@birkenfeld, @abalkin, @orsenthil, @merwok, @bitdancer

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/orsenthil'
closed_at = <Date 2010-11-07.13:21:58.207>
created_at = <Date 2010-10-29.05:26:04.216>
labels = ['type-bug', 'docs']
title = 'urlparse example is wrong'
updated_at = <Date 2010-11-08.02:37:27.093>
user = 'https://github.com/abalkin'

bugs.python.org fields:

activity = <Date 2010-11-08.02:37:27.093>
actor = 'r.david.murray'
assignee = 'orsenthil'
closed = True
closed_date = <Date 2010-11-07.13:21:58.207>
closer = 'orsenthil'
components = ['Documentation']
creation = <Date 2010-10-29.05:26:04.216>
creator = 'belopolsky'
dependencies = []
files = []
hgrepos = []
issue_num = 10226
keywords = []
message_count = 10.0
messages = ['119855', '119857', '119859', '119867', '119868', '119873', '119914', '119991', '120678', '120710']
nosy_count = 6.0
nosy_names = ['georg.brandl', 'belopolsky', 'orsenthil', 'eric.araujo', 'r.david.murray', 'docs@python']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue10226'
versions = ['Python 3.1', 'Python 2.7', 'Python 3.2']

[abalkin]

The following example in Doc/library/urlparse.rst is wrong

>>> urlparse('www.cwi.nl:80/%7Eguido/Python.html')
ParseResult(scheme='', netloc='', path='www.cwi.nl:80/%7Eguido/Python.html',
           params='', query='', fragment='')

In the actual output, scheme='www.cwi.nl'.

In addition, the preceding text is confusing and probably not grammatical:

"""
Otherwise, it is not possible to distinguish between netloc and path components, and would the indistinguishable component would be classified as the path as in a relative URL.
"""

Discovered while working on bpo-10225.

[abalkin]

Looks like I've been beaten again by make doctest picking up older python, but something is not right here:

In Python 2.6.5:

>>> urlparse('www.cwi.nl:80/%7Eguido/Python.html')
ParseResult(scheme='www.cwi.nl', netloc='', path='80/%7Eguido/Python.html', params='', query='', fragment='')

but in 2.7:

>>> urlparse('www.cwi.nl:80/%7Eguido/Python.html')
ParseResult(scheme='', netloc='', path='www.cwi.nl:80/%7Eguido/Python.html', params='', query='', fragment='')

and the text preceding the example in the doc does not really tell which is right.

[birkenfeld]

I think this is correct: it is the new behavior after the fix for bpo-754016 was committed.

[abalkin]

On Fri, Oct 29, 2010 at 2:15 AM, Georg Brandl <report@bugs.python.org> wrote:
..

I think this is correct: it is the new behavior after the fix for bpo-754016 was committed.

I agree. I kept the issue open because I cannot parse

"""
Otherwise, it is not possible to distinguish between netloc and path
components, and would the indistinguishable component would be
classified as the path as in a relative URL.
"""

[birkenfeld]

That's for Senthil to rephrase as intended :)

[orsenthil]

-   Otherwise, it is not possible to distinguish between netloc and path
-   components, and would the indistinguishable component would be classified
-   as the path as in a relative URL.
+   If the netloc does not start with '//', the module cannot distinguish it
+   from path and it would classify it as path component in the relative url.

How does this sound?

[merwok]

// is not part of the netloc in RFC terms, it’s a delimiter between components

[bitdancer]

How about this:

• If the scheme value is not specified, urlparse following the syntax
• specifications from RFC 1808, expects the netloc value to start with '//',
• Otherwise, it is not possible to distinguish between net_loc and path
• component and would classify the indistinguishable component as path as in
• a relative url.

+ Following the syntax specifications in RFC 1808, urlparse recognizes
+ a netloc only if it is properly introduced by '//'. Otherwise the
+ input must be presumed to be a relative URL and thus to start with
+ a path component.

However, it seems to me there is a bug here:

>>> urlparse.urlparse('www.k.com:80/path')
ParseResult(scheme='', netloc='', path='www.k.com:80/path', params='',
query='', fragment='')
>>> urlparse.urlparse('www.k.com:path')
ParseResult(scheme='www.k.com', netloc='', path='path', params='',
query='', fragment='')

I think the second one is correct and that the first one should produce

ParseResult(scheme='www.k.com', netloc='', path='80/path', params='',
query='', fragment='')

I haven't read all the way through the RFC again, though. But *one*
of the above is wrong.

[orsenthil]

Fixed the wordings in r86296(py3k), r86297(release31-maint) and r86298(release27-maint).

David, for the examples you mentioned, the first one's parsing logic follows the explanation that is written. It is correct.

For the second example, the port value not being a DIGIT exhibits such a behavior. I am unable to recollect the reason for this behavior.
Either the URL is invalid (PORT is not a DIGIT, and parse module is simply ignoring to raise an error - it's okay, given the input is invalid) or it needs to distinguish the ':' as a port separator from path separator for some valid urls.

I think, if we find a better reason to change something for the second scenario, we shall address that.