code: def file_crc32(filePath):
      
      crc = 0
      with open(filePath, 'rb') as f:
          for block in _file_iter(f, _BLOCK_SIZE):
              crc = binascii.crc32(block, crc) & 0xFFFFFFFF
      return crc
docs: 计算文件的crc32检验码:
  
      Args:
          filePath: 待计算校验码的文件路径
  
      Returns:
          文件内容的crc32校验码。