【发布时间】：2016-10-26 06:35:24
【问题描述】：
期望的行为：
我正在尝试在不同节点上获取许多不同长度的列表，将它们收集到一个节点中，然后让该主节点将它们放在一组中。这个列表在每个节点中被命名为rout_array。请注意，rout_array 中的元素只是整数，并且在节点间不唯一。
错误：
Traceback (most recent call last):
File "prout.py", line 160, in <module>
main()
File "prout.py", line 153, in main
num = DetermineRoutingNumber(steps, goal, vertexSetSize)
File "prout.py", line 129, in DetermineRoutingNumber
comm.Gather(send_buffer, recv_buffer, root = 0)
File "MPI\Comm.pyx", line 589, in mpi4py.MPI.Comm.Gather (c:\projects\mpi4py\src\mpi4py.MPI.c:97806)
File "MPI\msgbuffer.pxi", line 525, in mpi4py.MPI._p_msg_cco.for_gather (c:\projects\mpi4py\src\mpi4py.MPI.c:34678)
File "MPI\msgbuffer.pxi", line 446, in mpi4py.MPI._p_msg_cco.for_cco_send (c:\projects\mpi4py\src\mpi4py.MPI.c:33938)
File "MPI\msgbuffer.pxi", line 148, in mpi4py.MPI.message_simple (c:\projects\mpi4py\src\mpi4py.MPI.c:30349)
File "MPI\msgbuffer.pxi", line 93, in mpi4py.MPI.message_basic (c:\projects\mpi4py\src\mpi4py.MPI.c:29448)
KeyError: 'O'
当我的代码中没有字符串时，我不知道如何获得 'O' 的 KeyError。所有列表都包含整数，numpy 数组包含整数，这里唯一活动的字典只有整数作为键。需要注意的是，每个节点都会输出这个错误。
代码：
import numpy, math
from mpi4py import MPI
from sympy.combinatorics import Permutation as Perm
def GetEdges(size,file):
"""This function takes in a file of edges in a graph in the form 'u,v'
without quotes, where u and v are vertices of the graph. It then
generates a permutation that swaps those vertices, and returns these
transpositions."""
edgeFile = open(file, "r")
edges = []
for line in edgeFile:
line = line.strip()
line = line.split(",")
for vertex in line:
line[line.index(vertex)] = int(vertex)
edges.append(Perm([line], size = size))
edgeFile.close()
edges.append(Perm([[size - 1]], size = size))
return edges
def AreDisjoint(p1,p2):
"""This function determines whether or not two permutations move any
common elements, and returns the appropriate boolean."""
v1 = set(p1.support())
v2 = set(p2.support())
return len(v1 & v2) == 0
def GetMatchings(edges, maxMatching, size):
"""This function takes in a set of edges given by GetEdges(), and
generates all possible matchings in the given graph. It then converts
each matching into its rank given by lexicographical order, and appends
that rank to a set, which is then returned."""
stepDict = {1:set(edges)}
steps = set(edges)
for i in range(1,maxMatching):
temp = set()
for p1 in stepDict[1]:
for p2 in stepDict[i]:
newPerm = p1 * p2
if AreDisjoint(p1,p2) and newPerm not in steps:
temp.add(newPerm)
steps.add(newPerm)
stepDict[i+1] = temp
newSteps = set()
for step in steps:
newSteps.add(step.rank())
return newSteps
def FromRank(rank,level):
"""This function takes in a rank and size of a permutation, then returns
the permutation that lies at the rank according to lexicographical
ordering. """
lst = list(range(level + 1))
perm = []
while lst:
fact = math.factorial(len(lst) - 1)
index, rank = divmod(rank, fact)
perm.append(lst.pop(index))
assert rank == 0
return perm
def SplitArrayBetweenNodes(rank, rem, length):
"""This function takes in the rank of a node and any remainder after
dividing up an array between all the nodes. It then returns a starting
and ending partition index unique to each node."""
if rem != 0:
if rank in list(range(rem)):
if rank == 0:
part_start = 0
part_end = length
else:
part_start = rank * (length + 1)
part_end = part_start + length
else:
part_start = rank * length + rem
part_end = part_start + length - 1
else:
part_start = rank * length
part_end = part_start + length - 1
return part_start, part_end
def DetermineRoutingNumber(steps, goal, vertexSetSize):
"""This function takes in the matchings created by GetMatchings(),
and calculates all possible products between its own elements. It then
takes all unique products, and calculates all possible prducts between
the matching set and the previous output. This repeats until all
permutations of a given type are found. The level at which this occurs
is then returned."""
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
size = comm.Get_size()
length = len(steps)
rem = length % size
part_len = length // size
part_start, part_end = SplitArrayBetweenNodes(rank,rem, part_len)
permDict = {1: steps}
i = 1
while True:
rout_array = set()
work_array = set(list(permDict[i])[part_start:part_end + 1])
#Calculate all possible products
for p1 in permDict[1]:
for p2 in work_array:
p2_perm = Perm(FromRank(p2,vertexSetSize - 1))
p1_perm = Perm(FromRank(p1,vertexSetSize - 1))
new = p2_perm * p1_perm
if new(0) == 0 or new(0) == 1:
order = new.rank()
rout_array.add(order)
#All nodes send their work to master node
comm.Barrier()
send_buffer = numpy.array(rout_array)
sendcounts = numpy.array(comm.gather(len(rout_array), root = 0))
if rank == 0:
recv_buffer = numpy.empty(sum(sendcounts), dtype = int)
else:
recv_buffer = None
comm.Gatherv(sendbuf = send_buffer, recvbuf = (recv_buffer, sendcounts), root = 0)
#Generate input for next level of the loop, and weed out repeats.
permDict[i+1] = rout_array
for j in range(1,i+1):
permDict[i+1] = permDict[i+1] - permDict[j]
def main():
file = "EdgesQ2.txt"
maxMatching = 2
vertexSetSize = 4
edges = GetEdges(vertexSetSize, file)
steps = GetMatchings(edges, maxMatching, vertexSetSize)
goal = 2 * math.factorial(vertexSetSize-1)
num = DetermineRoutingNumber(steps, goal, vertexSetSize)
print(num)
main()
测试用例：
EdgesQ2.txt：
请注意，此示例中的 maxMatching = 2 和 vertexSetSize = 4。输出应该是3。
0,1
1,2
2,3
0,3
EdgesQ3.txt：
请注意此示例中的 maxMatching = 4 和 vertexSetSize = 8。输出应该是4。
0,1
0,3
0,4
1,2
1,5
2,3
2,6
3,7
4,5
4,7
5,6
6,7
【问题讨论】：
-
欢迎来到 SO。我冒昧地回答了您的根本问题，而不是
KeyError。请记住，通常需要发布minimal reproducible example 以获得调试帮助。您的代码很接近，但缺少rout_array、permDict、part_len以便能够重现该问题。