title: Input and output numpy arrays to h5py
body: <p>I have a Python code whose output is a <img src="https://i.stack.imgur.com/keJsR.png" alt="enter image description here"> sized matrix, whose entries are all of the type <code>float</code>. If I save it with the extension <code>.dat</code> the file size is of the order of 500 MB. I read that using <code>h5py</code> reduces the file size considerably. So, let's say I have the 2D numpy array named <code>A</code>. How do I save it to an h5py file?
  Also, how do I read the same file and put it as a numpy array in a different code, as I need to do manipulations with the array?</p>