title: how to get the memory address of a numpy array for C
body: <p>I constructed an numpy array::</p>
  
  <pre><code>a=np.ndarray([2,3]) 
  </code></pre>
  
  <p>then i want to see where its data are::</p>
  
  <pre><code>a.data 
  &gt;&gt;&gt;Out[213]: &lt;read-write buffer for 0x0482C1D0, size 48, offset 0 at 0x049E87A0&gt; 
  a.data 
  &gt;&gt;&gt;Out[214]: &lt;read-write buffer for 0x0482C1D0, size 48, offset 0 at 0x049E82A0&gt; 
  a.data 
  &gt;&gt;&gt;Out[215]: &lt;read-write buffer for 0x0482C1D0, size 48, offset 0 at 0x049E81C0&gt; 
  </code></pre>
  
  <p>...</p>
  
  <p>why every time the offset address is different?
  if i want to transfer the data to a c function using c_types by::</p>
  
  <pre><code>ctypes_array = (ctypes.c_char * a.size * 8).from_address(ptr) 
  </code></pre>
  
  <p>how should i get the value of ptr?</p>