2.4->2.5 current directory change?

[Chris Mellon]

On 26 Feb 2007 13:00:55 -0800, Ziga Seilnacht <ziga.seilnacht at gmail.com> wrote:
> On Feb 26, 7:44 pm, "Chris Mellon" <arka... at gmail.com> wrote:
> > This appears to be a change in behavior from Python 2.4 to Python 2.5,
> > which I can't find documented anywhere. It may be windows only, or
> > related to Windows behavior.
> >
> > In 2.4, the current directory (os.curdir) was on sys.path. In 2.5, it
> > appears to be the base directory of the running script. For example,
> > if you execute the file testme.py in your current working directory,
> > '' is on sys.path. If you execute c:\Python25\Scripts\testme.py, '' is
> > *not* on sys.path, and C:\Python25\Scripts is.
> >
> > That means if you run a Python script located in another directory,
> > modules/etc in your current working directory will not be found. This
> > makes .py scripts in the PYTHONHOME\Scripts file moderately useless,
> > because they won't find anything in the current working directory.
> >
> > I first noticed this because it breaks Trial, but I'm sure there are
> > other scripts affected by it. Is this desirable behavior? Is there
> > anything to work around it except by pushing os.curdir onto sys.path?
>
>
> The change was intentional and is mentioned in the NEWS file:
>
> - Patch #1232023: Stop including current directory in search path
>   on Windows.
>
> This unifies Python's behaviour across different platforms; the
> docs always said that the current directory is inserted *only*
> if the script directory is unavailable:
>
>     As initialized upon program startup, the first item of this list,
>     path[0], is the directory containing the script that was used to
>     invoke the Python interpreter. If the script directory is not
>     available (e.g. if the interpreter is invoked interactively or
>     if the script is read from standard input), path[0] is the empty
>     string, which directs Python to search modules in the current
>     directory first. Notice that the script directory is inserted
>     before the entries inserted as a result of PYTHONPATH.
>
> The old behaviour was never intentional and wasn't desired,
> because users could break an application simply by running it
> from a directory that contained inappropriately named files.
>
> For details see the bug report and patch submission:
> http://www.python.org/sf/1526785
> http://www.python.org/sf/1232023
>
> Ziga
>

Considering that it's a backwards incompatible breaking change
(although I understand why it was done), you'd think it deserved
mention in the more prominent "Whats new in Python 2.5" section on the
website, in addition to a one-liner in the NEWS file. Ah well, while
I'm sure I'm not the only one who ran into it, it doesn't seem to be
causing mass calamity and I know now.