title: Changing Values in multiindex pandas dataframe
body: <p>I have loaded a multiindex matrix from excel to a panda dataframe.</p>
  
  <pre><code>    df=pd.read_excel("filename.xlsx",sheet_name=sheet,header=1,index_col=[0,1,2],usecols="B:AZ")
  </code></pre>
  
  <p>The dataframe has three index colums and one header, so it has 4 indices. Part of the dataframe looks like this:</p>
  
  <p><img src="https://i.stack.imgur.com/YjgNK.png" alt="picture of part of dataframe"></p>
  
  <p>When I want to show a particular value, it works like this:</p>
  
  <pre><code>df[index1][index2][index3][index4]
  </code></pre>
  
  <p>I now want to change certain values in the dataframe. After searching through different forums for a while, it seemed like df.at would be the right method to do this. So I tried this:</p>
  
  <pre class="lang-py prettyprint-override"><code>df.at[index1,index2,index3,index4]=10 (or any random value)
  </code></pre>
  
  <p>but I got a <code>ValueError: Not enough indexers for scalar access (setting)!</code>. I also tried different orders for the indices inside the df.at-Brackets.</p>
  
  <p>Any help on this would be much appreciated!</p>