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POOrder a list by all item's digits in Python
 

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    <h1>I want to sort a list by each item's digit.</h1> <p>Example:</p> <pre><code>myCmpItem = '511' myList = ['111','222','333','444','555','123'] (some magic) mySortedList = ['111', '222', '333', '123', '444', '555'] </code></pre> <h1>How the algorithm should work:</h1> <ul> <li>Compare each digit of current item in myList with myCmpItem <ul> <li>For the first item in the list it would be like that:</li> <li>Difference between 5 and 1 is 4</li> <li>Difference between 1 and 1 is 0</li> <li>Difference between 1 and 1 is 0</li> <li>Difference between those two numbers is 4 (the sum of the digit comparison)</li> </ul></li> <li>Do the same for all other items</li> <li>Order the list by this calculated similarity</li> </ul> <p>I could code this with alot of for-loops, but I am actually looking for a faster way to do this. Is there any algorithm that does something like that? Fast?</p> <h1>Further Limitations</h1> <ul> <li>In my example all items have a length of 3, in the real scenario they have a length of 25</li> <li>All items have the same length, len(myList[x])==25 is always true</li> <li>Items can be strings, ints, floats or whatever fits better to the algorithm</li> <li>There are only digits between 1 and 5</li> </ul> <h1>Background</h1> <p>All item's digits are answers to questions and I want to find the most similar answer-set to a given answer-set. So "123" means that a user answered to Questions 1 = Answer 1, Question 2 = Answer 2, Question 3 = Answer 3. They are multiple choice questions with 25 questions in total (= length of 25) and there are always 5 different possibilites to answer (Those are the digits 1-5).</p> <p><em>PS: This is the first question I asked on Stackoverflow so please be kind with me. I already googled for hours but I could not find any solution, so I asked here. I hope that is fine. Also english is not my native language.</em></p> <h1>The Answer (thanks to all participants!)</h1> <p>@larsmans' answer (<a href="https://stackoverflow.com/a/10790714/511484">https://stackoverflow.com/a/10790714/511484</a>) explains very well how to solve this with reasonable speed. You can even speed up the algorithm by calculating the distances between every digit in advance, see @gnibbler's post (<a href="https://stackoverflow.com/a/10791838/511484">https://stackoverflow.com/a/10791838/511484</a>) All the other answers were also nice and correct, but I found that @larsmans had the best explanation. Thanks everybody once again for the help!</p>
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    1. COthanks Wooble, thats what I also thought, so I used strings here
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    2. COwhat if the difference is negative?
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    3. CO@AshwiniChaudhary its a relative distance so the sign can be skipped (abs).
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