title: How to apply math.ceil function to the part of objective function in python pulp
body: <p>Am trying to apply the <code>math.ceil</code> function on one part of the objective function in python-pulp. But, Am getting </p>
  
  <pre><code>"TypeError: must be real number, not LpAffineExpression" error.
  </code></pre>
  
  <p>Following is the example.</p>
  
  <pre><code>models = [A, B, C, D, E]
  modelCost = {A: 10, B: 15, C: 20, D: 25, E: 30}
  TotalModelsCost = pulp.lpSum([(model*modelCost[model]) for model in models])
  OverHeadCost = (math.ceil(pulp.lpSum([model for model in models])/4))*100
  
  prob += TotalModelsCost + OverHeadCost
  </code></pre>
  
  <p>How to apply the <code>ceil</code> function to <code>OverHeadCost</code>?</p>