This has been discussed on StackOverflow before - I am trying to find a good way to find the absolute path of a file object, but I need it to be robust to os.chdir(), so cannot use

f = file('test')
os.path.abspath(f.name)

Instead, I was wondering whether the following is a good solution - basically extending the file class so that on opening, the absolute path of the file is saved:

class File(file):

    def __init__(self, filename, *args, **kwargs):
        self.abspath = os.path.abspath(filename)
        file.__init__(self, filename, *args, **kwargs)

Then one can do

f = File('test','rb')
os.chdir('some_directory')
f.abspath # absolute path can be accessed like this

Are there any risks with doing this?