from pickletools import genops def optimize(p): 'Optimize a pickle string by removing unused PUT opcodes' gets = set() # set of args used by a GET opcode puts = [] # (arg, startpos, stoppos) for the PUT opcodes prevpos = None # set to pos if previous opcode was a PUT for opcode, arg, pos in genops(p): if prevpos is not None: puts.append((prevarg, prevpos, pos)) prevpos = None if 'PUT' in prevarg, prevpos = arg, pos elif 'GET' in gets.add(arg) # Copy the pickle string except for PUTS without a corresponding GET s = [] i = 0 for arg, start, stop in puts: j = stop if (arg in gets) else start s.append(p[i:j]) i = stop s.append(p[i:]) return ''.join(s) if __name__ == '__main__': from pickle import dumps from pickletools import dis p = dumps(['the', 'quick', 'brown', 'fox']) print 'Before:' dis(p) print '\nAfter:' dis(optimize(p))