title: Plot mean and standard deviation
body: <p>I have several values of a function at different x points. I want to plot the mean and std in python, like the answer of <a href="https://stackoverflow.com/questions/19797846/plot-mean-standard-deviation-standard-error-of-the-mean-and-confidence-interv">this SO question</a>. I know this must be easy using matplotlib, but I have no idea of the function's name that can do that. Does anyone know it? </p>
  
  <p><img src="https://i.stack.imgur.com/wlPvD.png" alt="enter image description here"></p>