python277

㈠ 求python代码编动态规划贝尔曼函数

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)

代码略长....

㈡ python文件中读取某一列数据然后输出数组匹配到另外一个文件中

我可以认为你是准备用这个文件第五列数据替换另一个文件的第五列数据么？

#下面的split里面我些的是空格，若不是空格分割，请替换
data1 = map(lambda x:x.strip().split(" ")[4],open("oct4.txt").readlines())
#这里我假设你要替换的文件是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)