用python将二进制整数或字符串写入文件

I have a string (it could be an integer too) in Python and I want to write it to a file. It contains only ones and zeros I want that pattern of ones and zeros to be written to a file. I want to write the binary directly because I need to store a lot of data, but only certain values. I see no need to take up the space of using eight bit per value when I only need three.

我在Python中有一个字符串(也可以是一个整数)，我想把它写到一个文件中。它只包含1和0，我希望将1和0的模式写入文件。我想直接写二进制，因为我需要存储很多数据，但只存储某些值。我认为，当我只需要3位时，不需要占用每个值使用8位的空间。

For instance. Let's say I were to write the binary string "01100010" to a file. If I opened it in a text editor it would say b (01100010 is the ascii code for b). Do not be confused though. I do not want to write ascii codes, the example was just to indicate that I want to directly write bytes to the file.

例如。假设我要将二进制字符串“01100010”写入一个文件。如果我用文本编辑器打开它，它会说b(01100010是b的ascii码)。我不想写ascii码，这个例子只是表示我想直接将字节写入文件。

Clarification:

澄清:

My string looks something like this:

我的字符串是这样的:

binary_string = "001011010110000010010"

It is not made of of the binary codes for numbers or characters. It contains data relative only to my program.

它不是由数字或字符的二进制代码组成的。它只包含与我的程序相关的数据。

5 个解决方案

#1

To write out a string you can use the file's .write method. To write an integer, you will need to use the struct module

要写出一个字符串，可以使用文件的.write方法。要编写一个整数，需要使用struct模块

import struct

#...
with open('file.dat', 'wb') as f:
    if isinstance(value, int):
        f.write(struct.pack('i', value)) # write an int
    elif isinstance(value, str):
        f.write(value) # write a string
    else:
        raise TypeError('Can only write str or int')

However, the representation of int and string are different, you may with to use the bin function instead to turn it into a string of 0s and 1s

但是，int和string的表示是不同的，您可以使用bin函数而不是将它转换成一个0和1的字符串

>>> bin(7)
'0b111'
>>> bin(7)[2:] #cut off the 0b
'111'

but maybe the best way to handle all these ints is to decide on a fixed width for the binary strings in the file and convert them like so:

但是，处理所有这些ints的最好方法可能是决定文件中的二进制字符串的固定宽度，并像这样转换它们:

>>> x = 7
>>> '{0:032b}'.format(x) #32 character wide binary number with '0' as filler
'00000000000000000000000000000111'

5 个解决方案

#1

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