You might also want to have a look at a numpy memmap viewed as a recarray.
from numpy import dtype, memmap, recarray # Define your record in the file, 4bytes for the real value, # and 4 bytes for the imaginary (assuming Little Endian repr) descriptor = dtype([("r", "<f4"), ("i", "<f4")]) # Now typecast a memap (a memory efficient array) onto the file in read only mode # Viewing it as a recarray means the attributes data.r and data.i are acessible as # ordinary numpy array data = memmap(filename, dtype=descriptor, mode='r').view(recarray) print "First 100 real values:", data.r[:100] --Slaunger -- http://mail.python.org/mailman/listinfo/python-list