title: How to list all attributes of sklearn.datasets object?
body: <p>Coming from R, where I can inspect the internal structure of any object with <code>str()</code>, I'm puzzled by how to do the same in Python. The standard is to use <code>dir(my_object)</code>, but it does not list all attributes, including very important ones. For example:</p>
  
  <pre><code>from sklearn import datasets
  iris = datasets.load_iris()
  dir(iris)
  </code></pre>
  
  <p><code>dir(iris)</code> does not list the most important attributes, such as <code>iris.data</code>, <code>iris.target</code>, etc.</p>
  
  <p>Am I supposed to read the docs to know about these attributes, or is there a way to find out just from looking inside the object?</p>