code: def regrep(filename, patterns, reverse=False, terminate_on_match=False,
             postprocess=str):
      
      compiled = {k: re.compile(v) for k, v in patterns.items()}
      matches = collections.defaultdict(list)
      gen = reverse_readfile(filename) if reverse else zopen(filename, "rt")
      for i, l in enumerate(gen):
          for k, p in compiled.items():
              m = p.search(l)
              if m:
                  matches[k].append([[postprocess(g) for g in m.groups()],
                                     -i if reverse else i])
          if terminate_on_match and all([
                  len(matches.get(k, [])) for k in compiled.keys()]):
              break
      try:
          # Try to close open file handle. Pass if it is a generator.
          gen.close()
      except:
          pass
      return matches
docs: A powerful regular expression version of grep.
  
      Args:
          filename (str): Filename to grep.
          patterns (dict): A dict of patterns, e.g.,
              {"energy": "energy\(sigma->0\)\s+=\s+([\d\-\.]+)"}.
          reverse (bool): Read files in reverse. Defaults to false. Useful for
              large files, especially when used with terminate_on_match.
          terminate_on_match (bool): Whether to terminate when there is at
              least one match in each key in pattern.
          postprocess (callable): A post processing function to convert all
              matches. Defaults to str, i.e., no change.
  
      Returns:
          A dict of the following form:
              {key1: [[[matches...], lineno], [[matches...], lineno],
                      [[matches...], lineno], ...],
              key2: ...}
          For reverse reads, the lineno is given as a -ve number. Please note
          that 0-based indexing is used.