error: unpack requires a bytes object of length 16

Question

下面的代码给我一个错误：

unpack requires a bytes object of length 16

https://docs.python.org/3.5/tutorial/stdlib2.html#brief-tour-of-the-standard-library-part-ii

11.3。使用二进制数据记录布局

import struct

with open('myfile.zip', 'rb') as f:
    data = f.read()

start = 0
for i in range(3):                      # show the first 3 file headers
    start += 14
    fields = struct.unpack('<IIIHH', data[start:start+16])
    crc32, comp_size, uncomp_size, filenamesize, extra_size = fields

    start += 16
    filename = data[start:start+filenamesize]
    start += filenamesize
    extra = data[start:start+extra_size]
    print(filename, hex(crc32), comp_size, uncomp_size)

    start += extra_size + comp_size     # skip to the next header

我这样创建了 'myfile.txt'（这可能是错误的，但我还能做什么？）：

0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001
0001000100010001

... 并将其压缩为 'myfile.zip'.

结果是：

b'myfile.txt' 0xb52979e4 42 6818
b'' 0x79e448ab 2798889 446824448
---------------------------------------------------------------------------
error                                     Traceback (most recent call last)
<ipython-input-7-d2e06ac7c75b> in <module>()
      7 for i in range(3):                      # show the first 3 file headers
      8     start += 14
----> 9     fields = struct.unpack('<IIIHH', data[start:start+16])
     10     crc32, comp_size, uncomp_size, filenamesize, extra_size = fields
     11

error: unpack requires a bytes object of length 16

我知道'IIIHH'表示4字节+4字节+4字节+2字节+2字节=16字节。但是，我不知道 ZIP 文件的结构。相同的代码对你们有用吗？我怎样才能使这项工作？

Answer 1

这里的问题是代码试图显示有关 zip 中前三个个文件的元数据，但您的 zip 只包含一个文件。

如果你改变

for i in range(3):                      # show the first 3 file headers

至

for i in range(1):

它会起作用。

error: unpack requires a bytes object of length 16

error: unpack requires a bytes object of length 16

python

binary

zip

unpack