Am Dienstag, 21. Januar 2014 14:38:34 UTC+1 schrieb Robert Voigtländer:
> > On Tue, Jan 21, 2014 at 03:17:43AM -0800, Robert Voigtl�nder wrote:
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> > > I have objects like this:
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> > > class Node(object):
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> > > def __init__(self, pos, parent, g , h):
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> > > self.pos = pos
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> > > self.parent = parent
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> > > self.g = g
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> > > self.h = h
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> > > self.f = g+h
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> > > I need to build a "list" of these objects. The amount is unknown.
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> > > On this list I need to regularly
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> > > 1. check if a specific item - identified by Node.pos - is in the list.
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> > > 2. find the object with the lowest Node.f attribute and update or remove
> > > it
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> First thanks to all who responded. Although I only partially understand your
> answers as I am a Python starter.
>
> What's clear to me is the difference between object and instance of an
> object. Just didn't explain it well.
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> Maybe I give some more info on what I need / want to do. I will also provide
> a working code example. Should have done this before.
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> I would very much appreciate a working example of what you mean. Then I have
> a chance to understand it. :-)
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> I would like to implement a class for a A* pathfinding algorithm. (there are
> ready libraries out there but I would like to learn it myself) This requires
> to maintain a list of nodes to be processed and nodes already processed. For
> new nodes I need to check if they are on one of the lists. I also need to
> regularly pick the node with the lowest value f from the list.
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> Here some working code. For one function I sill need a solution. Any better
> solution is welcome.
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> Thanks
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> Robert
Sorry - found a bug right after my post.
Here the corrected version.
class Node:
def __init__(self, pos, parent, g , h):
self.pos = pos
self.parent = parent
self.g = g
self.h = h
self.f = g+h
def isinlist(nodeToSeatch):
for item in openlist:
if item.pos == nodeToSeatch: return True
return False
def lowestF():
lowestF = ''
for item in openlist:
if item.f < lowestF:
lowestF = item.f
lowestFItem = item
return lowestFItem
def deleteItemWithPos(pos):
## need this function or different approach
pass
openlist=[]
openlist.append(Node((1,1),None,1,5))
openlist.append(Node((1,2),(1,1),4,6))
openlist.append(Node((1,3),(1,2),9,10))
for item in openlist: print item.pos, item.f
print isinlist((1,1))
print isinlist((1,5))
nextNode = lowestF()
print nextNode.pos, nextNode.f
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