Python AttributeError: ‘map‘ object has no attribute ‘extend‘_attributeerror: 'map' object has no attribute 'ext

C:\Users\kai\Desktop\CRC32-1-6位>python3 crc321-6.py
verification checksum: 0x308e1d5b (OK)
Traceback (most recent call last):
  File "C:\Users\kai\Desktop\CRC32-1-6位\crc321-6.py", line 3, in <module>
    crc32_reverse(0x308e1d5b,4)
  File "C:\Users\kai\Desktop\CRC32-1-6位\my_crc32.py", line 129, in crc32_reverse
    obj.run_reverse()
  File "C:\Users\kai\Desktop\CRC32-1-6位\my_crc32.py", line 109, in run_reverse
    patch.extend(last_4_bytes)
AttributeError: 'map' object has no attribute 'extend'

            for item in self.dfs(self.length - 4):
                patch = map(ord, item) ###Python 2.x 返回列表。
                patches = self.findReverse(desired, self.calc(patch, accum))
                for last_4_bytes in patches:
                    if all(p in self.char_set for p in last_4_bytes):
                        patch.extend(last_4_bytes)
                        print ('[find]: {1} ({0})&