title: line-by-line or named variable memory profiling in python
body: <p>I am looking for a memory profiler which shows memory usage per line or per variable.</p>
  <p>I tried with <code>memory-profiler</code>, which shows memory usage per line but the problem is it does not work in ipython environment.</p>
  <p>I tried <code>pympler</code>, which have a <code>track_class</code> and <code>track_object</code> function. But they can not track variable type like <code>list</code> or <code>dict</code> but predefined class or object.
  While trying to track list, I got following error:</p>
  <pre><code>TypeError: cannot create weak reference to 'list' object
  </code></pre>
  <p>I tried <code>objgraph</code>, which shows the type of variables but not pin point the variable. So there may be several <code>list</code>, but show output like this:</p>
  <pre><code>objgraph.show_growth(limit=3) 
  tuple                  5228     +5228
  function               1330     +1330
  wrapper_descriptor      967      +967 
  </code></pre>
  <p>How can I track variables (not predefined class object) or show memory usage per line in ipython environment?</p>