将路径重新定位到新的根目录的大多数pythonic方法

Question

I have the following:

a = "/my/absolute/path"
b = "my/relative/path"
root = "/new/root/dir"
print relocate_path(a, root)
print relocate_path(b, root)

I would like to get:

/new/root/dir/my/absolute/path
/new/root/dir/my/relative/path

How to effectively implement relocate_path in a pythonic way? Is there something like that in the standard library? (I have tried in os.path , but found nothing)

Answer 1

You need os.path.join for relative paths. In case of absolute path I think the best thing you can do is stripping the leading slash.

Something like this:

def relocate_path(new_root, path):
    return os.path.join(new_root, path.lstrip('/'))

To get a path relative to root given an absolute path you can also do:

>>> os.path.relpath('/absolute/path', '/')
'absolute/path'

but I don't think it's more crossplatform than just stripping the slash. I've tried playing with relpath on Windows a bit and I should say I have no idea how it works.

Answer 2

Just now I wrote a small python script, i don't know whether it can help you.

import re

def relocate_path(path,root):
    pattern = re.compile(r'^/')
    match = pattern.match(path)
    if match:
        return (root+path)
    else:
        return (root+"/"+path)