python277

㈠ 求python代碼編動態規劃貝爾曼函數

classNode(object):

def__init__(self,name):
self._name=name
self._value=None
self._from=None
self._next=[]

defsetValue(self,value):
self._value=value

defsetNext(self,node):
self._next.append(node)

defsetFrom(self,node):
self._from=node

defgetValue(self):
returnself._value

defgetNext(self):
returnself._next

defgetName(self):
returnself._name

defgetFrom(self):
returnself._from

classBFtree():

def__init__(self,dList):
self._dList=dList

defbfValue(self,start):
cur=start
ifcur.getNext()isnotNone:
fornodeincur.getNext():
path=[cur.getName(),node.getName()]
path.sort()
path=''.join(path)
value=cur.getValue()+self._dList[path]
ifnode.getValue()isNoneorvalue<node.getValue():
node.setValue(value)
node.setFrom(cur)
self.bfValue(node)

defmove(self,start,end):
print'From:',start.getName(),'to:',end.getName()
start.setValue(0)
self.bfValue(start)
trace=[end.getName()]
cur=end
whilecur.getFrom()isnotNone:
cur=cur.getFrom()
trace.append(cur.getName())
trace=reversed(trace)
print'Thepathis',''.join(trace),'andthevalueis',end.getValue()

#builidngnode
a=Node('A')
b=Node('B')
c=Node('C')
d=Node('D')
e=Node('E')
f=Node('F')
g=Node('G')
h=Node('H')

#buildtree
a.setNext(b)
a.setNext(c)
a.setNext(d)

b.setNext(a)
b.setNext(g)

c.setNext(a)
c.setNext(g)
c.setNext(e)

d.setNext(a)
d.setNext(e)

e.setNext(c)
e.setNext(b)
e.setNext(f)

f.setNext(e)

g.setNext(b)
g.setNext(c)
g.setNext(h)

h.setNext(g)

#builddistancelist
dList=dict();
dList['AB']=1
dList['AC']=2
dList['AD']=3
dList['BG']=1
dList['BE']=6
dList['CE']=2
dList['CG']=5
dList['DE']=4
dList['EF']=3
dList['GH']=4

#buildBFtree
tree=BFtree(dList)
tree.move(a,h)
tree.move(a,f)
tree.move(a,e)

代碼略長....

㈡ python文件中讀取某一列數據然後輸出數組匹配到另外一個文件中

我可以認為你是准備用這個文件第五列數據替換另一個文件的第五列數據么？

#下面的split裡面我些的是空格，若不是空格分割，請替換
data1 = map(lambda x:x.strip().split(" ")[4],open("oct4.txt").readlines())
#這里我假設你要替換的文件是oct5.txt
data2 = map(lambda x:x.strip().split(" "),open("oct5.txt").readlines())

data2_new = []
for line in data2:
line[4] = data1.pop(0)
data2_new.append(line)
file("oct5_new.txt"."w").writelines(data2_new)