(py3) [root@7-o-1 py-dag]# cat test.py 
from dag import DAG
dag = DAG()
dag.from_dict({'a': ['b', 'c','e'],
     'b': ['d','g'],
     'c': ['d'],
     'g':['i'],
     'i':[],
     'e':['gh','ox','wer'],
     'gh':[],
     'ox':[],
     'wer':[],
     'd': []})

def generate_excel(dag, row_start,col,excel_file):#参数分别为有向无环图图、开始写入的行,开始写入列，以及文件名
 import xlsxwriter#导入Excel操作模块
 workbook = xlsxwriter.Workbook(excel_file)#创建Excel文件
 worksheet = workbook.add_worksheet('testsheet')#创建工作簿
 #以下为部分格式的预定义（包含合并行格式，数字日期格式等）
 merge_format = workbook.add_format({
 'bold': 1,
 'border': 1,
 'align': 'left',
 'valign': 'vcenter'})

 cell_format = workbook.add_format({
 'bold': 1,
 'border': 1,
 'align': 'top',
 'valign': 'left'})

 date_format = workbook.add_format({
 'bold': 1,
 'border': 1,
 'align': 'top',
 'valign': 'left',
 'num_format': 'd mmmm yyyy'})

 num_format = workbook.add_format({
 'bold': 1,
 'border': 1,
 'align': 'top',
 'valign': 'left',
 'num_format': '0.0000%'})

 def get_node_leaves(node,ret = []):#用来返回一个节点的所有最终叶子结点
   downs = dag.downstream(node)#先获取当前节点的下一级节点
   if len(downs) < 1:#如果无下一级节点将直接将此节点添加到列表
    ret.append(node)
   else:#负责循环递归，将所有叶子结点添加到列表
    for inner_node in downs:
     get_node_leaves(inner_node,ret)
   return ret#返回节点列表

 def dag_visit(dag, node, r_idx,col):
  if node not in all_leaves:
   downstreams = dag.downstream(node)
   node_leaves = len(get_node_leaves(node,[]))#获取所有叶子的个数，用来判断是否进行合并行操作
   r_idx_end = r_idx+node_leaves-1
   if len(downstreams) == 1:#对于只有一个子节点的node应用write
    worksheet.write(col+str(r_idx), node,cell_format)
   else:#对于多余一个子节点的node应用merge_range
    worksheet.merge_range(col+str(r_idx)+':'+col+str(r_idx_end), node,merge_format)
   col = chr(ord(col)+1)#列+1，开始进入子节点遍历
   downstreams_len = len(downstreams)
   if len(downstreams) >0:
    row_next = r_idx
    for downstream in downstreams:
     subnode_leaves = len(get_node_leaves(downstream,[]))#获取当前节点的所有叶子用来为下一个节点的填充确定位移
     if downstream in all_leaves:
      subnode_leaves = 1
      if col == merge_to:#对于子节点为叶子并且跨度为1应用write
       worksheet.write(col+str(row_next), downstream,cell_format)
      else:#对于子节点为叶子结点但是跨度大于1应用merge_range
       merge_rg = col+str(row_next) +':'+merge_to+str(row_next)
       worksheet.merge_range(merge_rg, downstream,merge_format)
     else:#子节点非叶子结点进行递归遍历
      dag_visit(dag, downstream, row_next,col)
     #每访问一个子结点需要将row值增加方便下一个node正确填充，row的值是前一个结点的子节点个数
     row_next += subnode_leaves

  else:
   print(node)

 head_node = dag.ind_nodes()[0]
 all_leaves = dag.all_leaves()
 dag_depth = dag.dag_depth(head_node,0)
 merge_to= chr(ord(col)+dag_depth)#对于合并列的终结列index
 dag_visit(dag, head_node, row_start,col)#传递根节点进行遍历
 workbook.close()
generate_excel(dag,1,'A','test.xlsx')