title: How to find the index of an array within an array
body: <p>I have created an array in the way shown below; which represents 3 pairs of co-ordinates. My issue is I don't seem to be able to find the index of a particular pair of co-ordinates within the array. </p>
  
  <pre><code>import numpy as np
  
  R = np.random.uniform(size=(3,2))
  
  R
  
  Out[5]: 
  array([[ 0.57150157,  0.46611662],
     [ 0.37897719,  0.77653461],
     [ 0.73994281,  0.7816987 ]])
  
  R.index([ 0.57150157,  0.46611662])
  </code></pre>
  
  <p>The following is returned:</p>
  
  <pre><code>AttributeError: 'numpy.ndarray' object has no attribute 'index'
  </code></pre>
  
  <p>The reason I'm trying to do this is so I can extend a list, with the index of a co-ordinate pair, within a for-loop.</p>
  
  <p>e.g.</p>
  
  <pre><code>v = []
  for A in R:
  v.append(R.index(A)) 
  </code></pre>
  
  <p>I'm just not sure why the index function isn't working, and can't seem to find a way around it.</p>
  
  <p>I'm new to programming so excuse me if this seems like nonsense.</p>