title: Pandas - Multi-Index Slicing/Setting With String Wildcards
body: <p>Have looked around and really having a hard time figuring this one out.  I want
  to in a single line of code slice and set multiple cells of a pandas DataFrame
  to the same value.</p>
  
  <p>The blue highlighted portion is what I am trying to set.</p>
  
  <p>This Works to Set - but it is only a single value:</p>
  
  <pre><code>dframe2.ix[('virname1','int3', 'sysname1')]['Switchport_Voice_VLAN2'] = 'test'
  </code></pre>
  
  <p>Both These Work To Slice, But Not Set:</p>
  
  <pre><code>dframe2.iloc[dframe2.index.get_level_values(0) == 'virname1' ]['Switchport_Voice_VLAN2']
  
  
  dframe2.iloc['virname1', slice(None), 'sysname1']['Switchport_Voice_VLAN2']
  </code></pre>
  
  <p>Can someone advise if there is a better way to do this?</p>
  
  <pre><code>&gt;&gt;&gt; dframe2
                         Switchport_Voice_VLAN Switchport_Voice_VLAN2
  virname1 int1 sysname1                horses                    NaN
  virname2 int2 sysname2                   NaN                 horses
  virname1 int2 sysname1                horses                 newval
           int3 sysname1                horses                   test
           int4 sysname1                horses                 newval
  </code></pre>