Python二进制数据读取

urllib2 请求接收二进制响应，如下所示：

00 00 00 01 00 04 41 4D 54 44 00 00 00 00 02 41
97 33 33 41 99 5C 29 41 90 3D 71 41 91 D7 0A 47
0F C6 14 00 00 01 16 6A E0 68 80 41 93 B4 05 41
97 1E B8 41 90 7A E1 41 96 8F 57 46 E6 2E 80 00
00 01 16 7A 53 7C 80 FF FF

其结构为：

DATA, TYPE, DESCRIPTION
 
00 00 00 01, 4 bytes, Symbol Count =1
 
00 04, 2 bytes, Symbol Length = 4
 
41 4D 54 44, 6 bytes, Symbol = AMTD
 
00, 1 byte, Error code = 0 (OK)
 
00 00 00 02, 4 bytes, Bar Count =  2
 
FIRST BAR
 
41 97 33 33, 4 bytes, Close = 18.90
 
41 99 5C 29, 4 bytes, High = 19.17
 
41 90 3D 71, 4 bytes, Low = 18.03
 
41 91 D7 0A, 4 bytes, Open = 18.23
 
47 0F C6 14, 4 bytes, Volume = 3,680,608
 
00 00 01 16 6A E0 68 80, 8 bytes, Timestamp = November 23,2007
 
SECOND BAR
 
41 93 B4 05, 4 bytes, Close = 18.4629
 
41 97 1E B8, 4 bytes, High = 18.89
 
41 90 7A E1, 4 bytes, Low = 18.06
 
41 96 8F 57, 4 bytes, Open = 18.82
 
46 E6 2E 80, 4 bytes, Volume = 2,946,325
 
00 00 01 16 7A 53 7C 80, 8 bytes, Timestamp = November 26,2007
 
TERMINATOR
 
FF FF, 2 bytes,

如何读取这样的二进制数据？

提前致谢。

Update:

我使用以下代码尝试了前 6 个字节的结构模块：

struct.unpack('ih', response.read(6))

(16777216, 1024)

但它应该输出 (1, 4)。我看了一下手册，但不知道出了什么问题。

因此，这是我解释您提供的数据的最佳方法......：

import datetime
import struct

class Printable(object):
  specials = ()
  def __str__(self):
    resultlines = []
    for pair in self.__dict__.items():
      if pair[0] in self.specials: continue
      resultlines.append('%10s %s' % pair)
    return '\n'.join(resultlines)

head_fmt = '>IH6sBH'
head_struct = struct.Struct(head_fmt)
class Header(Printable):
  specials = ('bars',)
  def __init__(self, symbol_count, symbol_length,
               symbol, error_code, bar_count):
    self.__dict__.update(locals())
    self.bars = []
    del self.self

bar_fmt = '>5fQ'
bar_struct = struct.Struct(bar_fmt)
class Bar(Printable):
  specials = ('header',)
  def __init__(self, header, close, high, low,
               open, volume, timestamp):
    self.__dict__.update(locals())
    self.header.bars.append(self)
    del self.self
    self.timestamp /= 1000.0
    self.timestamp = datetime.date.fromtimestamp(self.timestamp)

def showdata(data):
  terminator = '\xff' * 2
  assert data[-2:] == terminator
  head_data = head_struct.unpack(data[:head_struct.size])
  try:
    assert head_data[4] * bar_struct.size + head_struct.size == \
           len(data) - len(terminator)
  except AssertionError:
    print 'data length is %d' % len(data)
    print 'head struct size is %d' % head_struct.size
    print 'bar struct size is %d' % bar_struct.size
    print 'number of bars is %d' % head_data[4]
    print 'head data:', head_data
    print 'terminator:', terminator
    print 'so, something is wrong, since',
    print head_data[4] * bar_struct.size + head_struct.size, '!=',
    print len(data) - len(terminator)
    raise

  head = Header(*head_data)
  for i in range(head.bar_count):
    bar_substr = data[head_struct.size + i * bar_struct.size:
                      head_struct.size + (i+1) * bar_struct.size]
    bar_data = bar_struct.unpack(bar_substr)
    Bar(head, *bar_data)
  assert len(head.bars) == head.bar_count
  print head
  for i, x in enumerate(head.bars):
    print 'Bar #%s' % i
    print x

datas = '''
00 00 00 01 00 04 41 4D 54 44 00 00 00 00 02 41
97 33 33 41 99 5C 29 41 90 3D 71 41 91 D7 0A 47
0F C6 14 00 00 01 16 6A E0 68 80 41 93 B4 05 41
97 1E B8 41 90 7A E1 41 96 8F 57 46 E6 2E 80 00
00 01 16 7A 53 7C 80 FF FF
'''

data = ''.join(chr(int(x, 16)) for x in datas.split())
showdata(data)

这会发出：

symbol_count 1
 bar_count 2
    symbol AMTD
error_code 0
symbol_length 4
Bar #0
    volume 36806.078125
 timestamp 2007-11-22
      high 19.1700000763
       low 18.0300006866
     close 18.8999996185
      open 18.2299995422
Bar #1
    volume 29463.25
 timestamp 2007-11-25
      high 18.8899993896
       low 18.0599994659
     close 18.4629001617
      open 18.8199901581

...这似乎非常接近你想要的，除去一些输出格式细节。希望这可以帮助！-）