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POOrdered Doubly Linked List
 

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    <p>Ok A question from assignment says to create an ordered doubly linked list...such that each object with lexicographically smaller name comes "Before" the other One...Like names in a Dictionary...also objects with same name can be arranged in any order...</p> <p>To link two objects I have <code>setBefore()</code> and <code>setAfter()</code> method... and I have done this much...but still don't know where I'm doing wrong..may be a little guidance from you guys can help me...</p> <p><code>atMe</code> is an object that is already present in the doubly linked list and <code>newFrob</code> is an object to be inserted...</p> <pre><code>def insert(atMe, newFrob): if newFrob.myName() &lt; atMe.myName(): if atMe.getBefore() == None: atMe.setBefore(newFrob) newFrob.setAfter(atMe) elif atMe.getBefore().myName()&lt;newFrob.myName(): atMe.getBefore().setAfter(newFrob) newFrob.setBefore(atMe.getBefore) atMe.setBefore(newFrob) newFrob.setAfter(atMe) else: insert(atMe.getBefore(),newFrob) elif newFrob.myName() &gt; atMe.myName(): if atMe.getAfter() == None: atMe.setAfter(newFrob) newFrob.setBefore(atMe) elif atMe.getAfter().myName()&gt;newFrob.myName(): atMe.getAfter().setBefore(newFrob) newFrob.setAfter(atMe.getAfter) atMe.setAfter(newFrob) newFrob.setBefore(atMe) else: insert(atMe.getAfter(),newFrob) elif newFrob.myName()==atMe.myName(): if atMe.getAfter() != None: newFrob.setAfter(atMe.getAfter()) newFrob.setBefore(atMe) if atMe.getAfter() != None: atMe.getAfter().setBefore(newFrob) atMe.setAfter(newFrob) </code></pre> <p>And this is the Frob Class to be used...</p> <pre><code>class Frob(object): def __init__(self, name): self.name = name self.before = None self.after = None def setBefore(self, before): self.before = before def setAfter(self, after): self.after = after def getBefore(self): return self.before def getAfter(self): return self.after def myName(self): return self.name </code></pre> <p>where Before and After are links to left and right objects in double linked list... objects from this class are to be inserted to double linked list...</p> <p>Example:</p> <pre><code>a=Frob('foo') b=Frob('bar') c=Frob('frob') d=Frob('code') code output insert(a,b) bar-&gt;foo insert(a,c) bar-&gt;foo-&gt;frob insert(b,d) bar-&gt;code-&gt;foo-&gt;frob </code></pre> <p>now suppose</p> <pre><code>code output insert(b,Frob('code')) bar-&gt;code-&gt;code-&gt;foo-&gt;frob </code></pre>
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    1. USBelphegor
    1. USadil
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    1. CO@downvoters: Please explain. As I can see, OP had clearly laid down the question, presented his best effort and still he cannot find a solution and would require help. He may not be quite apt with Python but we should help him out instead of downvoting.
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      1. USAbhijit
    2. COplease explain what you mean _exactly_ by a `Ordered Doubly Linked List`? explain how it should work, what methods it should implement... etc etc...
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      1. USInbar Rose
    3. CO@eumiro thanks...but still no improvement...
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      1. USadil
 

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