title: best way to store numpy arrays in ascii files
body: <p>I often have processed numpy arrays that come as a result of lengthy computations. I need to use them elsewhere in calculations. I currently 'pickle' them and unpickle the files into variables as and when I need them. </p>
  
  <p>I noticed for large data sizes (~1M data points), this is slow. I read elsewhere that pickling is not best way to store huge files. I would like to store and read them as ASCII files efficiently to load directly into a numpy array. What is the best way to do this? </p>
  
  <p>say I have a 100k x 3 2D array in a variable 'a'. I want to store it in an ASCII file and load it into a numpy array variable 'b'.</p>