python - How to unpack a binary file buffer into two variables? -

i have binary file contains 4-byte binary values represent set of 2 short int each. know can unpack single 4-byte binary value 2 short integers this:

from struct import unpack  fval = b'\xba\x1e\x99\x01' #actualy read file qualdip, azi = unpack('hh', fval) print(type(qualdip), qualdip) print(type(azi), azi)  >>> <class 'int'> 7866 >>> <class 'int'> 409 

now, want unpack entire buffer. moment doing:

qualdips = [] azis = [] open(bfile, 'rb') buf:     fval = buf.read(4)     while fval:         qualdip, azi = unpack('hh', fval)         azis.append(azi)         qualdips.append(qualdip)         fval = buf.read(4) 

which takes on minute 277mb file , seems produce huge memory overhead.

i unpack entire filebuffer directly 2 variables. how accomplish this?

i suspect struct.unpack_from friend, unsure how formulate format.

with open(bfile, 'rb') buf:     qualdip, azi = unpack_from('hh', buf) 

only extracts 2 values, , (i know number of elements of file)

with open(bfile, 'rb') buf:     qualdip, azi = unpack_from('72457091h72457091h', buf) 

expects ridiculous amount of output variables. so:

how do unpack entire filebuffer directly 2 variables?

i don't know way unpack values directly 2 lists, can unpack entire file tuple , slice in two:

fval = b'\xba\x1e\x99\x01' * 3 unpacked= unpack('3h3h', fval) qualdip = unpacked[0::2] azi = unpacked[1::2] 

alternatively, use islice create iterator, reduce memory consumption.

qualdip = islice(unpacked, 0, none, 2) azi = islice(unpacked, 1, none, 2)