title: Assign a numpy array to a specific cell of a pandas dataframe
body: <p>Is it possible to store a numpy array in a single pandas cell? For example, let's assume we have the following df</p>
  
  <pre><code>import pandas as pd
  import numpy as np
  df= pd.DataFrame(np.nan, columns =["A","B","C"], index =np.arange(5))
  </code></pre>
  
  <p>It is possible to set a specific cell as follows</p>
  
  <pre><code>df.ix[1,"A"]=2 # This works
  </code></pre>
  
  <p>However, if I try to assign an numpy array, it fails with a <code>ValueError: setting an array element with a sequence.</code> exception. </p>
  
  <pre><code>df.ix[1,"A"]=np.arange(5) #This fails
  </code></pre>
  
  <p>Is there any way to solve this? There is a similar <a href="https://stackoverflow.com/a/45548507/8943544">solution on SO</a> and it suggests to pass the values as numpy array as list but it seems not to work in my case.</p>
  
  <pre><code>df.ix[1,"A"]=list(np.arange(5)) #This also fails
  </code></pre>
  
  <p>Any suggestions?</p>