title: How to create a new list for each line in a file?
body: <p>I am trying to create a soduko styled program.
  A notepad/word document is uploaded into Python and I want Python to check:</p>
  
  <p>Each line (row) has the same number of characters
  Each column has the same number of characters
  No characters are repeated twice in either a column or in a row
  Every character is used once and only once per column and per row</p>
  
  <p>The file uploaded can either be a numerical soduko or an alphabetical soduko.</p>
  
  <p>So far, I have managed to load, open and read the document and append each line of the document as a list. Below I will show my coding for appending to a list:</p>
  
  <pre><code>my_list = [line.strip() for line in open(filename)]
  
  print (my_list)
  </code></pre>
  
  <p>But this puts all my lines inside a bigger list.
  For example, if my document read:</p>
  
  <pre><code>1 2 3
  2 3 1
  3 1 2
  </code></pre>
  
  <p>It would read my_list as follows: <code>[['1 2 3'], ['2 3 1'], ['3 1 2']]</code></p>
  
  <p>I'm relatively new to Python and have no idea how to count individual items from a list within a list so this is quite complicated for me.</p>
  
  <p>Any suggestions or tips on how to progress/alter my coding to make this easier for me?</p>