I have a large ASCII file (~100GB) which consists of roughly 1.000.000 lines of known formatted numbers which I try to process with python. The file is too large to read in comp
The np.genfromtxt function is a speed champion if you can get it to match you input format.
If not, then you may already be using the fastest method. Your line-by-line split-into-array approach exactly matches the SciPy Cookbook examples.