title: Convert one DataFrame row to flat list
body: <p>I new to Python and I'm therefore having trouble converting a row in a <code>DataFrame</code> into a flat <code>list</code>.  To do this I use the following code:</p>
  
  <p>Toy <code>DataFrame</code>:</p>
  
  <pre><code>import pandas as pd
  d = {
       "a": [1, 2, 3, 4, 5],
       "b": [9, 8, 7, 6, 5],
       "n": ["a", "b", "c", "d", "e"]
  }
  
  df = pd.DataFrame(d)
  </code></pre>
  
  <p>My code:</p>
  
  <pre><code>df_note = df.loc[df.n == "d", ["a", "b"]].values #convert to array
  df_note = df_note.tolist() #convert to nested list
  df_note = reduce(lambda x, y: x + y, df_note) #convert to flat list
  </code></pre>
  
  <p>To me this code appears to be both gross and inefficient.  The fact that I convert to an <code>array</code> before a <code>list</code> is what is causing the problem, i.e. the <code>list</code> to be nested.  That withstanding, I can not find a means of converting the row directly to a list.  Any advice?</p>
  
  <p>This question is not a dupe of <a href="https://stackoverflow.com/questions/19585280/convert-a-row-in-pandas-into-list">this</a>.  In my case, I want the list to be flat.</p>