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POList contents changing with each iteration
 

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  1. POList contents changing with each iteration
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    <p>So I am working on making a dictionary of subway stations in Boston and their neighbors for a bigger program. Each station belongs to a line, like blue or red, and these lines make up the whole entire subway system in Boston. But I am having trouble. here is my code so far:</p> <pre><code> for i in range(len(tuples)): for x in range(len(tuples[i][1])): print tuples neighbors=[] station=tuples[i][1][x] if tuples[i][1][-1]==station and station not in duplicates: line=0 for item in tuples: if station in item[1]: line=item[0] break neighbors.append((tuples[i][1][-2],line)) elif tuples[i][1][0]==station and station not in duplicates: line=0 for item in tuples: if station in item[1]: line=item[0] break neighbors.append((tuples[i][1][1],line)) elif station in duplicates: line=[] for item in tuples: if station in item[1]: line.append((item[0],tuples.index(item))) neighbors=[(tuples[i][1][x+1],tuples[i][1][x-1],line[0][0]),(tuples[line[1][1]][1][x+1],tuples[line[1][1]][1][x-1],line[1][0])] else: line=0 for item in tuples: if station in item[1]: line=item[0] break neighbors.append((tuples[i][1][x+1],tuples[i][1][x-1],line[0][0])) for neighbor in neighbors: subdict[station]={} for i in range(len(neighbor)-1): subdict[station].update({neighbor[i]:neighbor[-1]}) </code></pre> <p>So I ran it and got a syntax error indicating an index out of range error. This made no sense but then I printed out the individual stations and lists in tuple, and found that they kept changing. So in one iteration, the list of stations in one subway line was the same as expected, but then after that it was completely different. Only the first station in the list in one subway line remained the same; the rest were from different lines of the Boston subway.</p> <p>So can someone tell me whats going on in my code?</p>
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      1. PTAnswer
    1. This table or related slice is empty.
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    1. USicedwater
    1. USManav Dutta
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
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    1. VO
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      1. POList contents changing with each iteration
      1. This table or related slice is empty.
      1. VTDownMod
    2. VO
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      1. POList contents changing with each iteration
      1. This table or related slice is empty.
      1. VTDownMod
    3. VO
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      1. POList contents changing with each iteration
      1. This table or related slice is empty.
      1. VTDownMod
    1. CODo you have some example data? What line triggered the error? Why are you iterating over the tuples by index instead of iterating directly over its elements?
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      1. POList contents changing with each iteration
      1. USTim Pietzcker
    2. COYou should define a `Station` class with properties like line and neighbors (the list of linked stations and direction). A linked list should be more appropriate representation for this kind of data than a complex nested lists of lists.
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      1. POList contents changing with each iteration
      1. USPaulo Scardine
    3. COPlease be more specific with the details of the bug.
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      1. POList contents changing with each iteration
      1. USicedwater
 

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