title: Warning while modyfing some elements of a dataset
body: <p>I have some problems with modifying some elements of a dataset. I've imported it through <code>pd.read_csv</code> then I've added a column of the same length of the other and I'm trying to modifying some elements of this column, as below:</p>
  <pre><code>dataset['c_grid']=0.227809021
  for i in range(17,49):
      dataset.loc[i]['c_grid']=0.232309021
  </code></pre>
  <p>It returns this warning:</p>
  <blockquote>
  <p>SettingWithCopyWarning:<br />
  A value is trying to be set on a copy of a slice from a DataFrame</p>
  <p>See the caveats in the documentation: <a href="https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy" rel="nofollow noreferrer">https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy</a></p>
  </blockquote>
  <p>and it hasn't changed the element selected above. I've tried to read some documentations but I have not understood how to handle it.</p>