title: TypeError: 'DatetimeIndex' object is not callable
body: <p>I have the following data:</p>
  <pre><code>                High
   Date
   2017-07-17    150.90
   2017-07-18    150.13
   2017-07-19    151.42
   2017-07-20    151.74
   2017-07-21    150.44
   2017-07-24    152.44
  </code></pre>
  <p>I was trying to get the index by putting in value inside <code>Highs.index(values)</code> but am unable to get the index.</p>
  <pre><code>import datetime as dt
  from datetime import timedelta as td
  import pandas as pd
  import pandas_datareader.data as web
  import numpy as np
  
  start = dt.datetime(2017, 7, 15)
  df = web.DataReader('AAPL', 'google', start)
  highs = df['High']
  print('Index = ',highs.index(150.44))
  </code></pre>
  <p>When i use <code>print('Index = ',highs.index(150.44))</code> i get the type error:</p>
  <blockquote>
  <p>print('Index = ',highs.index(150.44))</p>
  <p>TypeError: 'DatetimeIndex' object is not callable</p>
  </blockquote>
  <p>Is their anyway to get the  datetime index using a particular value from the dataframe?</p>