How to write 1 byte to a binary file?

python filehandle writing

reza · Sep 7, 2016 · Viewed 7.5k times · Source

I've tried everything to write just one byte to a file in python.

i = 10
fh.write( six.int2byte(i) )

will output '0x00 0x0a'

fh.write( struct.pack('i', i) )

will output '0x00 0x0a 0x00 0x00'

I want to write a single byte with the value 10 to the file.

Answer

You can just build a bytes object with that value:

with open('my_file', 'wb') as f:
    f.write(bytes([10]))

This works only in python3. If you replace bytes with bytearray it works in both python2 and 3.

Also: remember to open the file in binary mode to write bytes to it.