title: How to use the split function on every row in a dataframe in Python?
body: <p>I want to count the number of times a word is being repeated in the review string</p>
  
  <p>I am reading the csv file and storing it in a python dataframe using the below line</p>
  
  <pre><code>reviews = pd.read_csv("amazon_baby.csv")
  </code></pre>
  
  <p>The code in the below lines work when I apply it to a single review. </p>
  
  <pre><code>print reviews["review"][1]
  a = reviews["review"][1].split("disappointed")
  print a
  b = len(a)
  print b
  </code></pre>
  
  <p>The output for the above lines were </p>
  
  <pre><code>it came early and was not disappointed. i love planet wise bags and now my wipe holder. it keps my osocozy wipes moist and does not leak. highly recommend it.
  ['it came early and was not ', '. i love planet wise bags and now my wipe holder. it keps my osocozy wipes moist and does not leak. highly recommend it.']
  2
  </code></pre>
  
  <p>When I apply the same logic to the entire dataframe using the below line. I receive an error message</p>
  
  <pre><code>reviews['disappointed'] = len(reviews["review"].split("disappointed"))-1
  </code></pre>
  
  <p>Error message: </p>
  
  <pre><code>Traceback (most recent call last):
    File "C:/Users/gouta/PycharmProjects/MLCourse1/Classifier.py", line 12, in &lt;module&gt;
      reviews['disappointed'] = len(reviews["review"].split("disappointed"))-1
    File "C:\Users\gouta\Anaconda2\lib\site-packages\pandas\core\generic.py", line 2360, in __getattr__
      (type(self).__name__, name))
  AttributeError: 'Series' object has no attribute 'split'
  </code></pre>