Try using the bytearray type (Python 2.6 and later), it's much better suited to dealing with byte data. Your try block would be just:
ba = bytearray(fh.read())
for byte in ba:
print byte & 1
or to create a list of results:
low_bit_list = [byte & 1 for byte in bytearray(fh.read())]
This works because when you index a bytearray you just get back an integer (0-255), whereas if you just read a byte from the file you get back a single character string and so need to use ord to convert it to an integer.
If your file is too big to comfortably hold in memory (though I'm guessing it isn't) then an mmap could be used to create the bytearray from a buffer:
import mmap
m = mmap.mmap(fh.fileno(), 0, access=mmap.ACCESS_READ)
ba = bytearray(m)
Top answer 1 of 3
61
Try using the bytearray type (Python 2.6 and later), it's much better suited to dealing with byte data. Your try block would be just:
ba = bytearray(fh.read())
for byte in ba:
print byte & 1
or to create a list of results:
low_bit_list = [byte & 1 for byte in bytearray(fh.read())]
This works because when you index a bytearray you just get back an integer (0-255), whereas if you just read a byte from the file you get back a single character string and so need to use ord to convert it to an integer.
If your file is too big to comfortably hold in memory (though I'm guessing it isn't) then an mmap could be used to create the bytearray from a buffer:
import mmap
m = mmap.mmap(fh.fileno(), 0, access=mmap.ACCESS_READ)
ba = bytearray(m)
2 of 3
9
You want to use ord instead of int:
if (ord(byte) & 0x01) == 0x01:
Python Guides
pythonguides.com › read-a-binary-file-into-a-byte-array-in-python
Read a Binary File into a Byte Array in Python - Python Guides
March 19, 2025 - We can also modify the values of specific bytes by assigning new values to the corresponding indices. Check out How to Check the Length of an Array in Python · Binary files often contain structured data that needs to be interpreted correctly. Python provides the struct module to unpack binary data into meaningful values. Here’s an example: import struct with open("data.bin", 'rb') as file: # Read a 32-bit integer and a 64-bit float binary_data = file.read(12) # 4 bytes for integer + 8 bytes for float value1, value2 = struct.unpack('>if', binary_data) print(f"Value 1: {value1}, Value 2: {value2}")
Python workflow for reading binary file into byte array
Is there a recommended way for reading and writing byte arrays in python inside Touch. I’m trying to understand how to use the Websocket DAT sendBinary method from code and hitting a more fundamental problem in that I can’t read a file off disk into a byte array. More on forum.derivative.ca
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June 18, 2014Whats a good way of writing an -int- as BYTES into a binary file (and later, reading it in too) ?
You might need the struct module to help you to get consistent sizing of the objects in binary format: https://docs.python.org/3/library/struct.html Python has "unlimited magnitude" integers - they just grow and grow to contain the required values, and different platforms (i.e. 32 vs 64 bit, intel vs. ARM etc.) can start with different "base" size integers. Using the struct module, you can make sure the appropriate representation is used. More on reddit.com
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February 7, 2022How to Read Binary File in Python?
Learn how to read binary files in Python using built-in functions for efficient data processing and manipulation. More on accuweb.cloud
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May 2, 2024Trying to read a binary file into an array one byte at a time and get the indexes of any matching sequences
Use of readline (you are using the <> spelling in your code) is wrong. This is meant for lined-based text, not binary. I would not recommend the use of sysopen/sysread as shown in a sibling post, you're bypassing PerlIO/buffering that way, and there is no reason to do that here. Use the normal open/ read instead, or the OO variant IO::Handle . use autodie qw(:all); my $buf; open my $fh, '<:raw', 'bam.png'; read $fh, $buf, 4; say "yup, that looks right" if $buf eq "\x89PNG"; read $fh, $buf, 4; say "this trick safeguards against accidental " . "newline mangling from misconfigured FTP clients" if $buf eq "\r\n\32\n"; while (read $fh, $buf, 1) { # rest of the file, one by one printf "0x%02x\n", ord $buf; } close $fh; More on reddit.com
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August 28, 2022Utk
marz.utk.edu › python › binary-files
Binary Files – Stephen Marz
The code above takes a bytes object, copies it into a byte array, changes the ‘s’ to a ‘z’, and copies it back. Notice that I had to use the ord(“z”), which is a special function that gives me the integer representation of a lowercase z. NOTE: Reading and writing to binary files uses the immutable bytes object.
Python Guides
pythonguides.com › python-read-a-binary-file
How to Read a Binary File in Python
November 4, 2025 - Another efficient way to read binary files in Python is to use the readinto() method. This method reads bytes directly into a pre-allocated buffer, which can be a bytearray or a memoryview.
GeeksforGeeks
geeksforgeeks.org › python › reading-binary-files-in-python
Reading Binary Files in Python - GeeksforGeeks
3 weeks ago - The readlines() method reads the file line by line and returns a list of byte strings. Each element in the list represents one line from the binary file. ... readlines() method reads all lines into a list, and the for loop prints each line as ...
YouTube
youtube.com › programgpt
python read binary file into byte array - YouTube
Download this code from https://codegive.com Title: Reading Binary Files into Byte Arrays in Python: A Step-by-Step TutorialIn Python, working with binary fi...
Published December 11, 2023 Views 99
W3docs
w3docs.com › python
Reading binary file and looping over each byte
Here is an example code snippet that demonstrates how to read a binary file and loop over each byte in Python: with open("file.bin", "rb") as binary_file: # Read the entire file into a byte array byte_array = binary_file.read() # Loop through ...
Fedingo
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How to Read Binary File in Python - Fedingo
July 23, 2025 - In such cases you can easily do this using list() function as shown below. file = open("/home/ubuntu/data.bin","rb") arr=list(file.read(4)) print(arr) file.close() In the above code, we open the file in binary mode to read.
Python Morsels
pythonmorsels.com › reading-binary-files-in-python
Reading binary files in Python - Python Morsels
May 16, 2022 - When you read a binary file in Python, you'll get back bytes.
DaniWeb
daniweb.com › programming › software-development › threads › 515440 › reading-an-entire-binary-file
python - Reading an entire binary file [SOLVED] | DaniWeb
January 22, 2018 - Okay. I just found bytearray() which has accomplished my goals by: with open("portrait1.dng", "rb") as binaryfile : myArr = bytearray(binaryfile.read()) with open("readfile.raw", "wb") as newFile: newFile.write(myArr)
TouchDesigner
forum.derivative.ca › beginners
Python workflow for reading binary file into byte array - Beginners - TouchDesigner forum
June 18, 2014 - Is there a recommended way for reading and writing byte arrays in python inside Touch. I’m trying to understand how to use the Websocket DAT sendBinary method from code and hitting a more fundamental problem in that I can’t read a file off disk into a byte array.
Scaler
scaler.com › home › topics › reading binary files in python
Reading binary files in Python - Scaler Topics
February 26, 2024 - Create a byte array using the array module, specifying the 'B' type code for unsigned bytes. Read the binary data into this byte array using the fromfile() method, and you're all set to manipulate the data with ease.
LinuxQuestions.org
linuxquestions.org › questions › linux-newbie-8 › python-read-binary-file-into-array-4175547091
python read binary file into array
hello pros! im quite a newbie in python. please help me out! so i have a hex file, that is about 2821 sector size. i want to create an array for every
Reddit
reddit.com › r/learnpython › whats a good way of writing an -int- as bytes into a binary file (and later, reading it in too) ?
r/learnpython on Reddit: Whats a good way of writing an -int- as BYTES into a binary file (and later, reading it in too) ?
February 7, 2022 -
Lets say I have two ints 35400, 364. I need to write these into a binary file one after the other.
How do you do write that int , and how do you open that file and read those ints in later?
(Using Path. if possible)
Top answer 1 of 4
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You might need the struct module to help you to get consistent sizing of the objects in binary format: https://docs.python.org/3/library/struct.html Python has "unlimited magnitude" integers - they just grow and grow to contain the required values, and different platforms (i.e. 32 vs 64 bit, intel vs. ARM etc.) can start with different "base" size integers. Using the struct module, you can make sure the appropriate representation is used.
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There's many ways. Here's the first one that comes to mind for me: filename = Path('myfile.bin') # assuming you want 4-byte (32-bit) unsigned integers with open(filename, 'wb') as f: f.write((35400).to_bytes(4, 'big')) f.write((364).to_bytes(4, 'big')) with open(filename, 'rb') as f: print(int.from_bytes(f.read(4), 'big')) print(int.from_bytes(f.read(4), 'big'))
Finxter
blog.finxter.com › home › learn python blog › python read binary file
Python Read Binary File – Be on the Right Side of Change
April 10, 2022 - The bytearray() method returns a bytearray object which is an array of bytes. Line [4] writes the variable array to the file opened earlier. Line [5] closes the previously opened file. Reading from a binary file is similar to the steps taken above.
Delft Stack
delftstack.com › home › howto › python › read binary files in python
How to Read Binary File in Python | Delft Stack
March 13, 2025 - The most straightforward way to read a binary file in Python is by using the built-in open() function. This function allows you to open a file in binary mode, enabling you to read its contents byte by byte.
Linux Hint
linuxhint.com › read-binary-files-in-python
How to Read Binary Files in Python – Linux Hint
# Open a file handler to create a binary file file_handler = open("string.bin", "wb") # Add two lines of text in the binary file file_handler.write(b"Welcome to LinuxHint.\nLearn Python Programming.") # Close the file handler file_handler.close() # Open a file handler to create a binary file file=open("number_list.bin","wb") # Declare a list of numeric values numbers=[10,30,45,60,70,85,99] # Convert the list to array barray=bytearray(numbers) # Write array into the file file.write(barray) file.close()
Accuweb
accuweb.cloud › home › how to read binary file in python?
How to Read Binary File in Python?
May 2, 2024 - Binary files often contain structured fields like integers and floats. Python’s struct module converts raw bytes into Python values.
IT trip
en.ittrip.xyz › python
Mastering Byte Arrays and Binary Files in Python: A Complete Guide | IT trip
November 4, 2023 - To convert a byte array to a binary file, you write the byte array to the file as shown above. Conversely, to convert a binary file to a byte array, you read the binary file and convert the bytes object to a bytearray object.
Quora
quora.com › How-do-I-read-a-binary-file-in-Python-3
How to read a binary file in Python 3 - Quora
Answer (1 of 3): You is open with the ‘rb’ mode, and then use read(…). Don’t use readline(..), readlines(…) to try to read the file ( as it will look for end of lines) and don’t try to use a for loop either, as that also works with end of lines. an example would be : [code]with ...