title: writing to .csv file in python not producing expected results
body: <p>I have been experimenting with writing to a csv file lately and stumbled across a problem. I have a for loop running through a list of items, and would like to rewrite this list in a .csv file, with each element of the list being in a new row. So, I structured the code as follows.     </p>
  
  <pre><code>import csv 
  
  groceries = ["banana", "apple", "orange", "orange", "milk", "orange", 
           "banana"]
  
  file_name = "an_example_file_here"
  
  banana_count = 0
  apple_count = 0
  orange_count = 0 
  milk_count = 0
  
  for i in groceries :
      w = csv.writer(open(file_name + ".csv", "w")) #writing to .csv
      if i == "banana":
          banana_count += 1
          w.writerow(["banana"])
      elif i == "apple":
          apple_count += 1
          w.writerow(["apple"])
      elif i == "orange":
          orange_count += 1
          w.writerow(["orange"])
      elif i == "milk":
          milk_count +=1 
          w.writerow(["milk"])
  
  w.writerow(["banana_count = ", str(banana_count)],)
  w.writerow(["apple_count = ", str(apple_count)],)
  w.writerow(["orange_count = ", str(orange_count)],)
  w.writerow(["milk_count = ", str(milk_count)],)     
  </code></pre>
  
  <p>I expected to get a csv file looking something like: 
  banana, apple, orange, orange, milk, orange, banana, banana_count = 2, apple_count = 1, orange_count = 3, milk_count = 1  </p>
  
  <p>But, the actual file I am getting looks like: 
  banana, banana_count = 2, apple_count = 1, orange_count = 3, milk_count = 1  </p>
  
  <p>I am not sure why, any help appreciated. Thank you! </p>