title: What do I have to to when it says: "AttributeError: 'function' object has no attribute 'append'"?
body: <p>I was doing a Codecademy Challenge when I came across the problem that following message was appearing when I wanted to check my answer: <code> estimate_insurance_cost.append((&quot;Maria&quot;, maria_insurance_cost)) AttributeError: 'function' object has no attribute 'append'</code></p>
  <pre><code>def estimate_insurance_cost(name, age, sex, bmi, num_of_children, smoker):
    estimated_cost = 250*age - 128*sex + 370*bmi + 425*num_of_children + 24000*smoker - 12500
    print(name + &quot;'s Estimated Insurance Cost: &quot; + str(estimated_cost) + &quot; dollars.&quot;)
    return estimated_cost
   
  # Estimate Maria's insurance cost
  maria_insurance_cost = estimate_insurance_cost(name = &quot;Maria&quot;, age = 31, sex = 0, bmi = 23.1, num_of_children = 1, smoker = 0)
  
  # Estimate Rohan's insurance cost
  rohan_insurance_cost = estimate_insurance_cost(name = 
  &quot;Rohan&quot;, age = 25, sex = 1, bmi = 28.5, num_of_children = 3, smoker = 0)
  
  # Estimate Valentina's insurance cost
  valentina_insurance_cost = estimate_insurance_cost(name = &quot;Valentina&quot;, age = 53, sex = 0, bmi = 31.4, num_of_children = 0, smoker = 1)
  
  
  names = [&quot;Maria&quot;, &quot;Rohan&quot;, &quot;Valentina&quot;]
  insurance_costs = [&quot;4150.0&quot;, &quot;5320.0&quot;, &quot;35210.0&quot;]
  insurance_data = zip(names, insurance_costs)
  print(insurance_data)
  insurance_data = list(zip(names, insurance_costs))
  print(insurance_data)
  
  estimate_insurance_cost.append((&quot;Maria&quot;, maria_insurance_cost))
  estimate_insurance_cost.append((&quot;Rohan&quot;, rohan_insurance_cost))
  estimate_insurance_cost.append((&quot;Valentina&quot;, valentina_insurance_cost))
  print(estimate_insurance_cost)
  </code></pre>