title: How to put constant in the first position when using statsmodel?
body: <p>I am trying to run a regression by using statsmodels of python. But the problem is that because I used fillna(1) to fill the dataframe, so there are some regressor as a constant.</p>
  <p>When I use</p>
  <pre><code>sm.OLS(y,x).fit().params
  </code></pre>
  <p>The order of these parameters is wrong, like this</p>
  <pre><code>    coeff
  x1  0.7017
  x2  0.0143
  x3  -1.0361
  x4  -0.0033
  x5  0.7583
  x6  -0.0081
  x7  -0.4451
  x8  -0.0024
  const   0.0153
  x9  0.0153
  x10 0.0153
  x11 0.0153
  x12 0.0153
  x13 0.0153
  x14 0.0153
  x15 0.0153
  x16 0.0153
  x17 0.0153
  </code></pre>
  <p>Because from x9 to x17 are constants.
  Could anyone solve this problem? Thanks in advance!</p>