[Python-checkins] r53800 - in python/trunk: Lib/encodings/__init__.py Misc/NEWS

[Brett Cannon]

On 2/15/07, M.-A. Lemburg <mal at egenix.com> wrote:
> On 2007-02-15 23:54, brett.cannon wrote:
> > Author: brett.cannon
> > Date: Thu Feb 15 23:54:39 2007
> > New Revision: 53800
> >
> > Modified:
> >    python/trunk/Lib/encodings/__init__.py
> >    python/trunk/Misc/NEWS
> > Log:
> > Update the encoding package's search function to use absolute imports when
> > calling __import__.  This helps make the expected search locations for encoding
> > modules be more explicit.
>
> Your change does not make the import absolute - to the contrary: we
> now have a relative import.
>

Right, but I just associate it with the absolute import PEP and the
term.  Probably could have called it a "new-style import" or
something.

> Please change that back to the original scheme which is indeed an
> absolute import.

Why?  What's wrong with a relative import?

> If you want to make sure that the search function
> is not importing from encodings.encodings, then you can add
> a 0 parameter as last parameter to __import__().

Right.  But that will essentially do the same thing I just committed
since what you are proposing will grab 'encodings' from sys.modules,
pull out its __path__ entry, and then do the import from there.  What
I did above skips that look up for 'encodings' and instead uses the
module that the function was defined in.

-Brett


> The other changes
> are not necessary.
>
> Thanks.
>
> > One could use an explicit value for __path__ when making the call to __import__
> > to force the exact location searched for encodings.  This would give the most
> > strict search path possible if one is worried about malicious code being
> > imported.  The unfortunate side-effect of that is that if __path__ was modified
> > on 'encodings' on purpose in a safe way it would not be picked up in future
> > __import__ calls.
> >
> >
> > Modified: python/trunk/Lib/encodings/__init__.py
> > ==============================================================================
> > --- python/trunk/Lib/encodings/__init__.py    (original)
> > +++ python/trunk/Lib/encodings/__init__.py    Thu Feb 15 23:54:39 2007
> > @@ -93,8 +93,10 @@
> >          if not modname or '.' in modname:
> >              continue
> >          try:
> > -            mod = __import__('encodings.' + modname,
> > -                             globals(), locals(), _import_tail)
> > +            # Import equivalent to `` from .modname import *``.
> > +            # '*' is used so that __import__ returns the desired module and not
> > +            # 'encodings' itself.
> > +            mod = __import__(modname, globals(), locals(), ['*'], 1)
> >          except ImportError:
> >              pass
> >          else:
> >
> > Modified: python/trunk/Misc/NEWS
> > ==============================================================================
> > --- python/trunk/Misc/NEWS    (original)
> > +++ python/trunk/Misc/NEWS    Thu Feb 15 23:54:39 2007
> > @@ -128,6 +128,9 @@
> >  Library
> >  -------
> >
> > +- Have the encoding package's search function dynamically import using absolute
> > +  import semantics.
> > +
> >  - Patch #1647484: Renamed GzipFile's filename attribute to name.
> >
> >  - Patch #1517891: Mode 'a' for ZipFile now creates the file if it
> > _______________________________________________
> > Python-checkins mailing list
> > Python-checkins at python.org
> > http://mail.python.org/mailman/listinfo/python-checkins
>
> --
> Marc-Andre Lemburg
> eGenix.com
>
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