This is really driving me crazy.
In one cell, I change
$Path by removing from it un-needed paths that I do not want for the duration of a computation I will be doing.
Immediatly after, in new cell, I type $Path and see it was changed ok.
Now, I open a new cell, and do the same. I type $Path again, and now I see some of the Paths I removed are back again! Here is a screen shot from my notebook now
You can see the variable $Path now has changed, on its own.
This is what I type
$Path =DeleteCases[$Path, "C:\\Users\\me"]; $Path =DeleteCases[$Path, "."]; $Path =DeleteCases[$Path,"C:\\Program Files\\Wolfram Research\\Mathematica\\8.0.4\\AddOns\\LegacyPackages"]; $Path =DeleteCases[$Path,"C:\\Users\\me\\AppData\\Roaming\\Mathematica\\Autoload"]; $Path =DeleteCases[$Path,"C:\\Users\\me\\AppData\\Roaming\\Mathematica\\Kernel"]; $Path =DeleteCases[$Path,"C:\\Users\\me\\AppData\\Roaming\\Mathematica\\Applications"]; $Path =DeleteCases[$Path,"C:\\ProgramData\\Mathematica\\Applications"]; $Path =DeleteCases[$Path,"C:\\ProgramData\\Mathematica\\Autoload"]; $Path =DeleteCases[$Path,"C:\\ProgramData\\Mathematica\\Kernel"]; $Path=DeleteCases[$Path,"C:\\Program Files\\Wolfram Research\\Mathematica\\8.0.4\\Documentation\\English\\System"];
Then in new cell
Then in new cell the same. And now the $Path has been reset.
I noticed this when I was calling Leonid function he posted, and in it, it uses
$Path, but I noticed I was getting packages that should not show up since I changed the $Path before calling it.
This is really strange. I am using V 8.0.4 on windows 7
Just installed version 9. Not able to reproduce this. Using the same PC, same notebook, same steps. So it looks like, whatever it was, is fixed in Version 9.