How to write int array [0,1,2,...] in binary to a file using Python script

Question

I'm new to Python. I want to generate a 100K binary file. The file contents will be (in hex):

00000000 00000001 00000002 00000003
00000004 00000005 00000006 00000007
...

I read some examples, but they all write a string to a text file. That's not what I want.

Do you want literal zeros, commas, and x's in your file? If so, should there be spaces after the commas? — user2357112
– user2357112, Commented Mar 28, 2014 at 4:16

Community · Accepted Answer · 2017-05-23 10:31:49Z

4

First, you can use the struct module to pack each number into a four-byte binary string. (See: Convert a Python int into a big-endian string of bytes)

Then, just loop from 0-25,000 and write each number to your file. Since each number is four bytes, this will produce a 100K file. For example:

import struct

f = open("filename","wb")
for i in range(25000):
    f.write(struct.pack('>I', i))
f.close()

edited May 23, 2017 at 10:31

CommunityBot

11 silver badge

answered Mar 28, 2014 at 4:14

Carter Sande

1,87915 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

3uc1id Over a year ago

if all of his values will fit in 8 bits, he could just use chr, correct?

Carter Sande Over a year ago

@Broseph He could just use chr if he wanted 8-bit numbers, but he wanted 32-bit binary numbers in the file.

3uc1id Over a year ago

Oh yes, my mistake. It is still possible to do this without struct, but that would be pointless. Unless this is homework and the teacher wants them to play with bits, lol.

Collectives™ on Stack Overflow

How to write int array [0,1,2,...] in binary to a file using Python script

1 Answer 1

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related