使用 python 将字节反向 AB CD 转换为 CD AB
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byte reverse AB CD to CD AB with python
提问by james28909
I have a .bin file, and I want to simply byte reverse the hex data. Say for instance @ 0x10 it reads AD DE DE C0, want it to read DE AD C0 DE.
我有一个 .bin 文件，我想简单地对十六进制数据进行字节反转。比如说@0x10它读AD DE DE C0，要它读DE AD C0 DE。
I know there is a simple way to do this, but I am am beginner and just learning python and am trying to make a few simple programs to help me through my daily tasks. I would like to convert the whole file this way, not just 0x10.
我知道有一种简单的方法可以做到这一点，但我是初学者，刚刚学习 Python，我正在尝试制作一些简单的程序来帮助我完成日常任务。我想以这种方式转换整个文件，而不仅仅是 0x10。
I will be converting at start offset 0x000000 and blocksize/length is 1000000.
我将在起始偏移量 0x000000 处进行转换，块大小/长度为 1000000。
here is my code, maybe you can tell me what to do. i am sure i am just not getting it, and i am new to programming and python. if you could help me i would very much appreciate it.
这是我的代码，也许你可以告诉我该怎么做。我确定我只是没有得到它，而且我是编程和 python 的新手。如果你能帮助我，我将不胜感激。
def main():
infile = open("file.bin", "rb")
new_pos = int("0x000000", 16)
chunk = int("1000000", 16)
data = infile.read(chunk)
reverse(data)
def reverse(data):
output(data)
def output(data):
with open("reversed", "wb") as outfile:
outfile.write(data)
main()
and you can see the module for reversing, i have tried many different suggestions and it will either pass the file through untouched, or it will throw errors. i know module reverse is empty now, but i have tried all kinds of things. i just need module reverse to convert AB CD to CD AB. thanks for any input
并且您可以看到用于反转的模块，我尝试了许多不同的建议，它要么原封不动地传递文件，要么抛出错误。我知道模块 reverse 现在是空的，但我已经尝试了各种方法。我只需要反向模块即可将 AB CD 转换为 CD AB。感谢您提供任何意见
EDIT: the file is 16 MB and i want to reverse the byte order of the whole file.
编辑：该文件是 16 MB，我想反转整个文件的字节顺序。
采纳答案by Raymond Hettinger
In Python 2, the binary file gets read as a string, so string slicing should easily handle the swapping of adjacent bytes:
在 Python 2 中，二进制文件作为字符串读取，因此字符串切片应该可以轻松处理相邻字节的交换：
>>> original = '\xAD\xDE\xDE\xC0'
>>> ''.join([c for t in zip(original[1::2], original[::2]) for c in t])
'\xde\xad\xc0\xde'
In Python 3, the binary file gets read as bytes. Only a small modification is need to build another array of bytes:
在 Python 3 中，二进制文件被读取为字节。只需要一个小的修改来构建另一个字节数组：
>>> original = b'\xAD\xDE\xDE\xC0'
>>> bytes([c for t in zip(original[1::2], original[::2]) for c in t])
b'\xde\xad\xc0\xde'
You could also use the <and >endianessformat codes in the struct moduleto achieve the same result:
您还可以在struct 模块中使用<和>endianess格式代码来实现相同的结果：
>>> struct.pack('<2h', *struct.unpack('>2h', original))
'\xde\xad\xc0\xde'
Happy byte swapping:-)
快乐字节交换:-)
回答by Tim Morgan
Python has a list operator to reverse the values of a list --> nameOfList[::-1]
Python 有一个列表运算符来反转列表的值 --> nameOfList[::-1]
So, I might store the hex values as string and put them into a list then try something like:
因此，我可能会将十六进制值存储为字符串并将它们放入列表中，然后尝试以下操作：
def reverseList(aList):
rev = aList[::-1]
outString = ""
for el in rev:
outString += el + " "
return outString
回答by grawee
In Python 3.4 you can use this:
在 Python 3.4 中你可以使用这个：
>>> data = b'\xAD\xDE\xDE\xC0'
>>> swap_data = bytearray(data)
>>> swap_data.reverse()
the result is
结果是
bytearray(b'\xc0\xde\xde\xad')
回答by u4751247
data = b'\xAD\xDE\xDE\xC0'
reversed_data = data[::-1]
print(reversed_data)
# b'\xc0\xde\xde\xad'
