title: Nested for loop using dict
body: <p>I am doing a Coursera python exercise and having trouble writing my code.</p>
  <p>The question is as following:</p>
  <blockquote>
  <p>Write a program to read through the <code>mbox-short.txt</code> and figure out who has the sent the greatest number of mail messages. The program looks for 'From ' lines and takes the second word of those lines as the person who sent the mail.</p>
  <p>The program creates a Python dictionary that maps the sender's mail address to a count of the number of times they appear in the file. After the dictionary is produced, the program reads through the dictionary using a maximum loop to find the most prolific committer.</p>
  </blockquote>
  <p>The sample text file is in this line:
  <a href="http://www.pythonlearn.com/code/mbox-short.txt" rel="nofollow noreferrer">http://www.pythonlearn.com/code/mbox-short.txt</a></p>
  <p>And the expected output should be:</p>
  <pre><code>cwen@iupui.edu 5
  </code></pre>
  <p>This is my code:</p>
  <pre><code>name = raw_input(&quot;Enter file:&quot;)
  if len(name) &lt; 1 : name = &quot;mbox-short.txt&quot;
  handle = open(name)
  count = dict()
  
  for line in handle:
      word = line.split()
      if line.startswith('From '):
          email = word[1]
          for sender in email:
              if sender not in count:
                  count[sender] = count.get(sender, 0) + 1
  
  bigcount = None
  bigname = None
  for name,count in count.items():
      if bigname is None or count &gt; bigcount:
          bigname = name
          bigcount = count
  print bigname, bigcount
  </code></pre>
  <p>The output I have is:</p>
  <pre><code>. 1
  </code></pre>
  <p>I think there is something wrong in &quot;for sender in email&quot; part, but couldn't figure out how it results in the undesired output.</p>