code: def load(self, f, precache=None):
          
          precache = precache or self.get_opt('cache') or False
          nodes = None
          if isinstance(f, file_):
              path = os.path.abspath(f.name)
  
          else:
              path = os.path.abspath(f)
              f = open(f)
  
          cache_path = os.path.splitext(path)[0] + '.ccss'
  
          if precache and os.path.exists(cache_path):
              ptime = os.path.getmtime(cache_path)
              ttime = os.path.getmtime(path)
              if ptime > ttime:
                  dump = open(cache_path, 'rb').read()
                  nodes = pickle.loads(dump)
  
          if not nodes:
              src = f.read()
              nodes = self.scan(src.strip())
  
          if precache:
              f = open(cache_path, 'wb')
              pickle.dump(nodes, f, protocol=1)
  
          self.parse(nodes)
          return ''.join(map(str, nodes))
docs: Compile scss from file.
              File is string path of file object.