title: python class attributes to pandas dataframe
body: <p>I would like to populate a pandas dataframe from attributes of a list of classes generated via 'append'. (not sure this is the right term to describe 'allFoo' below
  Here is a stripped down example code:</p>
  
  <pre><code>class foo(object):
  def __init__(self,input):
      self.val=input
      #in real life, there will be many more attributes in this class
  allFoo=[];
  for i in range(10):
      allFoo.append(foo(i))
  </code></pre>
  
  <p>now I would like to define a new pandas data frame 'df' that gets populated from allFoo.val (and not any other attributes)</p>
  
  <p>something like this: </p>
  
  <pre><code>df[0]=foo[0].val
  df[1]=foo[1].val
  </code></pre>
  
  <p>etc</p>
  
  <p>I am coming from matlab where I would try something like this:
  dataFrame=allFoo[:].val</p>
  
  <p>how can I achieve this in python/pandas?</p>