title: AttributeError: 'Series' object has no attribute 'merge'
body: <p>I want to merge two dataset into one
  here is the code I have written</p>
  <pre><code>application_prev_data = application_data.merge(previous_application, left_on='SK_ID_CURR', right_on='SK_ID_CURR', how='inner')
  
  application_prev_data.head() 
  </code></pre>
  <p>But it keeps giving me an error message.. what should I do? any suggestions?</p>
  <pre><code>AttributeError                            Traceback (most recent call last)
  &lt;ipython-input-30-f97d87cba0a8&gt; in &lt;module&gt;
  ----&gt; 1 application_prev_data = application_data.merge(previous_application, left_on='SK_ID_CURR', right_on='SK_ID_CURR', how='inner')
        2 application_prev_data.head()
  
  ~\anaconda3\lib\site-packages\pandas\core\generic.py in __getattr__(self, name)
     5128             if self._info_axis._can_hold_identifiers_and_holds_name(name):
     5129                 return self[name]
  -&gt; 5130             return object.__getattribute__(self, name)
     5131 
     5132     def __setattr__(self, name: str, value) -&gt; None:
  
  AttributeError: 'Series' object has no attribute 'merge'
  </code></pre>
  <p>I have the latest version of pandas (or at least that's what I believe)</p>
  <pre><code>Python: 3.7.6 (default, Jan  8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)]
  Numpy: 1.18.1
  Pandas: 1.1.1
  MatplotLib: 3.1.3
  Seaborn: 0.10.0
  Scipy: 1.4.1
  </code></pre>