title: Appending row to dataframe with concat()
body: <p>I have defined an empty data frame with</p>
  <pre><code>df = pd.DataFrame(columns=['Name', 'Weight', 'Sample'])
  </code></pre>
  <p>and want to append rows in a for loop like this:</p>
  <pre><code>for key in my_dict:
     ...
     row = {'Name':key, 'Weight':wg, 'Sample':sm}
     df = pd.concat(row, axis=1, ignore_index=True) 
  </code></pre>
  <p>But I get this error</p>
  <pre><code>cannot concatenate object of type '&lt;class 'str'&gt;'; only Series and DataFrame objs are valid
  </code></pre>
  <p>If I use <code>df = df.append(row, ignore_index=True)</code>, it works but it seems that <code>append</code> is deprecated. So, I want to use <code>concat()</code>. How can I fix that?</p>