title: How to get slopes of data in pandas dataframe in Python?
body: <p>I want to get slopes of dataset in the dataframe (either using linear regression model or sk-learn model).</p>
  
  <pre><code>df1:
     A     B     C     D  
  0  15    25    55    100
  1  15.5  25.5  56    101
  2  14.8  24.5  54.2  99.8
  3  15.5  25.5  55.5  102
  4  16    26    57    108
  </code></pre>
  
  <p>I want to get slopes of each dolumn ('A', 'B', 'C', 'D') in the form of pd.Series. Can you help me on this? Thank you.</p>
  
  <p>The output I want is something like below (I used just dummy numbers, not real slopes!):</p>
  
  <pre><code>slopes:
  A  2.5
  B  2.8
  C  3.1
  D  3.3
  </code></pre>