Python MS项目前身递归与for循环

Question

我已将 MS 项目文件提取为 CSV。它相当大（40 000 行），我正在尝试创建一个 Python 脚本，该脚本可以打印出任务/里程碑/依赖项之前的所有任务。

问题在于具有多个前置任务的任务。我已经存储了这些以“~”分隔的内容。

#Starting ID
MSid = 80329

#Subroutine FindPredesessors(MSid)
def FindPred(MSid):
#Get element[id] from the array                
    print(MSid)
    #Predecessors of task
    preds = arrMAX[MSid][1]
    #List of split milestones
    spID = spad.split('~')

    #Attempt to loop through Function for each milestone in the split list
    for h in range(len(spID)):         
        print(spID[h])
        print(h)
        FindPred(int(spID[h]))

FindPred(MSid)

我能做的最好的就是下面的输出

80329
['80326', '83171']
['80324', '80432']
['80323']
''

我可以得到最左边的路径，但我似乎无法返回并在拆分列表的其余部分循环该函数

Answer 1

看来您需要Breadth First Search。这个想法是：

1. 将所需的事件ID放入queue
2. 当队列不为空时
   • get() current id 来自它
   • 将current的所有前辈放入队列中

因此，您将首先访问所选事件的所有前辈，然后访问其所有前辈，依此类推。

#!/usr/bin/env python3
from queue import Queue

size = 6
# in assumption you have devided strings to lists of ids
# -1 means that event has no predecessor.
preds = [[-1], [-1], [-1], [0], [1, 2], [3, 4]]

def bfs(start):
    """ Prints path of Depth first search given predecessors for all events"""
    q = Queue()
    q.put(start)

    while not q.empty():
        current = q.get()
        currentPreds = preds[current]
        print(current, end=' ')
        # or you can print them with predecessors
        # print(currentId =', current, '| preds:', currentPreds)

        for c in currentPreds:
            if not visited[c] and c != -1:
                q.put(c)
    print()

bfs(5)