Testing For Directories Outside the Tree
In Leonardo, I have a case where I am concatenating a fixed directory x and a relative path y.
I want to avoid the result being outside the directory tree rooted by x.
Any ideas?
Is
root = os.path.abspath(x) path = os.path.abspath(os.path.join(x, y)) assert path.startswith(root)
a reasonable approach?
Actually, I should clarify: y isn't a relative path as such. y can be '/' which should taken to mean x. So perhaps what I want is:
root = os.path.abspath(x) path = os.path.abspath(os.path.normpath(x + os.sep + y)) assert path.startswith(root)
I ruled out
assert os.path.normpath(x + os.sep + y).startswith(x)
For the case where 'x' is itself relative.
Comments (2)
James Tauber on May 24, 2005:
os.path.normpath(y)[1:] won't work as y doesn't always start with slash. However, os.path.normpath(y).lstrip("/") would do the trick, I think.
Think of it as a chroot to x and then a cd to y. So "/foo" and "foo" have the same effect as values for y.
Last Modified: May 24, 2005
Author: James Tauber
Ian Bicking on May 24, 2005:
how about os.path.abspath(os.path.join(x, os.path.normpath(y)[1:]))