收集Python MPI中的结构列表？

Question

我目前正在尝试传达struct对象的列表，但我遇到了一个错误：

    Traceback (most recent call last):
    File "Primary_secondary_co-sim.py", line 509, in <module>
    sm_clear_all(params, curr_pri_timestep, soln)
    File "/home/gridsan/jvineet9/vvc_sims/code/sm_clear_all.py", line 
    162, in sm_clear_all
    node_num = soln_node['node_num']
    TypeError: list indices must be integers or slices, not str
    Primary job  terminated normally, but 1 process returned
    a non-zero exit code. Per user-direction, the job has been 
    aborted.
    ----------------------------------------------------------------- 

    mpirun detected that one or more processes exited with non-zero 
    status, thus causing
    the job to be terminated. The first process to do so was:

    Process name: [[56840,1],1]
    Exit code:    1

这是我的代码：

from mpi4py import MPI
import os

data = [4,5]
num_SMOs = 5
solns_list = []

comm = MPI.COMM_WORLD
size = comm.Get_size()
rank = comm.Get_rank()

name = MPI.Get_processor_name()
pid = os.getpid()

idx = range(num_SMOs)
myidx = idx[rank:len(idx):size] 

for node in myidx:

    soln_node = structtype()

    # Add some data fields to struct
    soln_node.node_num = node
    soln_node.XX = data

    solns_list.append(soln_node)

# All nodes send their solns to rank 0

solns_nodes_all = comm.gather(solns_list, root=0)

if rank == 0:

    for soln_node in solns_nodes_all: 

        node_num = soln_node.node_num
        data = soln_node.XX

这是struct python对象的定义：

class structtype:
    def __init__(self):
        pass

我在solns_nodes_all中的soln_node处得到错误：节点。我希望Solns_nodes_all成为构造的结构列表，但是看起来它已成为MPI收集步骤之后的列表吗？

Answer 1

mpi4py s 收集操作从节点获取单个值，并将这些返回值放入列表中。您返回列表，因此将它们放入列表的列表中。如果您打算返回多个值，但希望平面列表迭代，则可以

import itertools

for soln_node in itertools.chain.from_iterable(solns_nodes_all):
    node_num = soln_node.node_num
    data = soln_node.XX

通过打印SOLNS_NODES_ALL的值来将其链接在一起：您可能已经找到了这一点：

[
  [<__main__.structtype object at 0x7ff148535c70>, <__main__.structtype object at 0x7ff148535700>],
  [<__main__.structtype object at 0x7ff148535ee0>, <__main__.structtype object at 0x7ff148535dc0>],
  [<__main__.structtype object at 0x7ff148535f40>]
]

的一般模式收集是这样的：

Node 1 returns A
Node 2 returns B
Node 3 returns C
Gathered into [A, B, C]

因此，如果您说a = [struct（struct（），struct（）]，...然后收集的内容为[[struct（struct（），struct （）]，...