title: Replacing pandas cell value with a new list generates ValueError: Must have equal len keys and value when setting with an iterable
body: <p>I would like to update the value of a cell that takes a list with a new updated list. However, when I try to replace the value using <code>.iloc</code> I get a <code>ValueError</code>.</p>
  <pre class="lang-py prettyprint-override"><code>d = {'title':['GrownUps', 'Toy Story', 'Toy Story', 'Avatar', 'Avatar', 'Avatar'], 'year': [[&quot;Hello&quot;, &quot;World&quot;],
                                                                                              [&quot;Not&quot;, &quot;Object&quot;, &quot;!&quot;],
                                                                                              1995, 2000, 2005, 2006]}
  dataset_SO=pd.DataFrame(d)
  
  dataset_SO.iloc[0,1]=[&quot;hi&quot;, &quot;cat&quot;, &quot;dog&quot;] #this line produces the ValueError
  </code></pre>
  <blockquote>
  <p>ValueError: Must have equal len keys and value when setting with an iterable</p>
  </blockquote>
  <p>I know it might be a silly question, however trying to make this <code>[&quot;hi&quot;, &quot;cat&quot;, &quot;dog&quot;]</code> an object, like <code>np.object0([&quot;hi&quot;, &quot;cat&quot;, &quot;dog&quot;])</code>. Or <a href="https://stackoverflow.com/questions/48000225/must-have-equal-len-keys-and-value-when-setting-with-an-iterable">this question</a> didn't help me to solve my issue.</p>