title: how to extract highest price using datareader python
body: <p>I want to extract the highest price but I dont know how here is my code:</p>
  <pre><code>import pandas
  import pandas_datareader.data as pdr
  import datetime as dt
  
  start = dt.datetime(2021,1,29)
  end = dt.datetime(2021,2,18)
  df = pdr.DataReader('BTC-USD','yahoo',start,end)
  </code></pre>
  <p>it returns cloumns and i want to print just the highest price</p>