code: def _loadcache(cachefile):
      
      cache = {}
      if os.path.exists(cachefile):
          with open(cachefile) as f:
              for line in f:
                  line = line.split()
                  if len(line) == 2:
                      try:
                          cache[int(line[0])] = float(line[1])
                      except:
                          pass
      return cache
docs: Returns a dictionary resulting from reading a likelihood cachefile