I'm working on a little audio project and part of it requires using wave files and flac files. Im trying to figure out how to read the metadata in each and how to add tags manually. I'm having trouble figuring out how to read the bytes as they are.
I have been referencing this page and a couple others to see the full format of a Wave file however for some wave files I get some discrepancies. I want to be able to see the hexadecimal bytes in order to see what differences are occurring.
Using simply open('fname', 'rb') and read, only returns the bytes as strings. Using struct.unpack has worked for some wave files however it is limited to printing as strings, ints, or shorts and I can't see exactly what is going wrong when I use it. Is there any other way I can read this file in hex?
Thanks
I assume that you just want to display the content of a binary file in hexadecimal. First, you do not need to use Python for that, as some editors to it natively, for example vim.
Now assuming you have a string that you got by reading a file, you can easily change it to a list of hexadecimal values:
with open('fname', 'rb') as fd: # open the file
data = rd.read(16) # read 16 bytes from it
h = [ hex(ord(b)) for b in data] # convert the bytes to their hex value
print (h) # prints a list of hexadecimal codes of the read bytes
Related
I am working with binary data. I have a file containing 2KB of binary data. I have used the following code to read the file and then print it. I have also tried to view the file contents using hexdump in the terminal. I am getting different outputs 1 and 2 (shown in attached screenshots) of the same file in python and hexdump. I am assuming it might be due to the encoding scheme used by python? I am very naive about working with binary data. Can anyone kindly check it and let me know the reasons for this? I also want to know if that's the correct way of reading a large binary file?
print("First File \n");
f1 = open("/data/SRAMDUMP/dataFiles/first.bin","rb")
num1 = list(f1.read())
print(num1)
f1.close()
I am assuming it might be due to the encoding scheme used by python?
There is no "encoding scheme" hexdump formats binary data as hex (two nibbles per byte), you've converted the binary contents of the file to a list which yields a list of integers (since that's what bytes are in python).
If you want to convert bytes to printable hex in Python, use the bytes.hex method. If you want something similar to hexdump, you'll need to take care of slicing, spacing and carriage-return-ing.
A slow version would simply read the file 2 bytes per 2 bytes, hex them, print them, then linebreak every 16 bytes. Python 3.8 adds formatting facilities to bytes.hex() meaning you can even more easily read bytes 16 by 16 with a separator every two, though that doesn't exactly match hexdump's format:
f = open(sys.argv[1], 'rb')
it = iter(functools.partial(f.read, 16), '')
for i, b in enumerate(it):
print(f'{16*i:07x} {b.hex(" ", 2)}')
Also beware that hexdump follows the platform's endianness by default which is... rarely what you want, and will not match your Python output. hexdump -C prints bytes in the file order.
Hello everyone!
I am currently working on a project and i need to automate the things on it using file handling..there is a file in '.dat' format and i want to extract the data from it..the data present in that is in the form of hex..and by getting these hex values i need to perform serial port communication..i can access this dat file from a tool named hex editor and can see the values from it..but the problem is that i do not want the complete data from that file i need to extract it in segments..i tried to read it but it reads it completely and i got some garbage values also in the output..
i will try to upload a screenshot of the hex editor and the values which i want to extract from it..so please antbody help me out in this
Open your .dat file in binary mode, access the data as per your need.
Use 'rb' parameters in open() method for reading in binary mode.
with open('input.dat', 'rb') as f:
data = f.read() # complete binary data will be available in 'data'
first_byte = data[0] # access individual byte like this
second_byte = data[1]
send_uart(data[:10]) # Send first 10 bytes
I know it looks like it has been answered before, but I can't seem to find a solution for this issue. I have a CSV file that contains very long strings of Base64 encoded images (~5mb each). I enabled the CSV field size limit to max. There are several of the images decoded separated by columns then a few values that are only a couple of words long. I can read these through print(row[7]) for example no problem. The images won't print the base64 strings, and i'm trying to decode them and save them to the filesystem but they end up being empty. Any thoughts?
fh = open("~path~/image.png", "wb")
x = base64.b64decode(row[1])
fh.write(x)
fh.close()
Thanks for any help!
EDIT: Works now. CSV split on python seems to act a little different than in Java. The empty values came up due to the csv being saved differently than the exporting tool I used indicated, so it was left with values ("8",,"data:image/png;base64,IR0BRR....",...). I didn't catch the empty space before, which is why it was showing blank, and then I also attempted to append the data:image/png part to the beginning of itself since I believed that python string split would split the comma after base64 like Java would. After adjusting for this, the image correctly saves in my filesystem.
I have a binary file (link) that I would like to open and read contents of with Python. How are such binary files opened and read with Python? Any specific modules to use for such an operation.
The 'b' flag will get python to treat the file as a binary, so no modules are needed. Also you haven't provided a purpose for having python read a binary file with a question like that.
f = open('binaryfile', 'rb')
print(f.read())
Here is an Example:
with open('somefile.bin', 'rb') as f: #the second parameter "rb" is used only when reading binary files. Term "rb" stands for "read binary".
data = f.read() #we are assigning a variable which will read whatever in the file and it will be stored in the variable called data.
print(data)
Reading a file in python is trivial (as mentioned above); however, it turns out that if you want to read a binary file and decode it correctly you need to know how it was encoded in the first place.
I found a helpful example that provided some insight at https://www.devdungeon.com/content/working-binary-data-python,
# Binary to Text
binary_data = b'I am text.'
text = binary_data.decode('utf-8') #Trans form back into human-readable ASCII
print(text)
binary_data = bytes([65, 66, 67]) # ASCII values for A, B, C
text = binary_data.decode('utf-8')
print(text)
but I was still unable to decode some files that my work created because they used an unknown encoding method.
Once you know how it is encoded you can read the file bit by bit and perform the decoding with a function of three.
For some reason, I cannot get a simple string to be output to a binary file with python.
Here is my code:
strin = bytes(strin, '3DFILE')
dataH = struct.pack('s', strin)
outFile.write(dataH)
I'm trying to write a 3D model exporter for a game I am making with blender. can someone please help me out here, or give me an example? I get the error that string is not defined.
Python 3 strings are sequences of unicode characters. The characters are abstract, and they have no binary representation until you say what encoding should be used.
If you have binary data, you can write it to the binary file (opened with binary mode like outFile = open(filename, 'wb') ... outFile.close()) without problem. However, writing binary data to the file opened in text mode cannot be done. It was different in Python 2 where strings were actually sequences of bytes and even the open text file object did not care.