code: def value(self):
          
          # This slightly convoluted calculation is equivalent to df's "Use%";
          # it calculates the percentage of FS usage as a proportion of the
          # space available to *non-root users*. Technically this means it can
          # exceed 100% (when FS is filled to the point that only root can write
          # to it), hence the clamp.
          vfs = os.statvfs(self.filesystem)
          used = vfs.f_blocks - vfs.f_bfree
          total = used + vfs.f_bavail
          return min(1.0, used / total)
docs: Returns the current disk usage as a value between 0.0 and 1.0 by
          dividing :attr:`usage` by 100.