title: What does [i,:] mean in Python?
body: <p>So I'm finished one part of this assignment I have to do. There's only one part of the assignment that doesn't make any sense to me. </p>
  
  <p>I'm doing a LinearRegression model and according to others I need to apply <code>ans[i,:] = y_poly</code> at the very end, but I never got an answer as to why. </p>
  
  <p>Can someone please explain to me what <code>[i,:]</code> means? I haven't found any explanations online.</p>