title: Creating Dictionaries from arrays in Python
body: <p>I have 3 numpy arrays :</p>
  
  <pre><code>a = numpy.array([['x','y']])
  b = numpy.array([['x1','y1']])
  c = numpy.array([['x2','y2']])
  </code></pre>
  
  <p>I want to create a dictionary as:</p>
  
  <pre><code>d={'x': ['x1','x2'], 'y':['y1','y2']}
  </code></pre>
  
  <p>How do I create such a dictionary?</p>