I have read a little about mptt solution and I'm trying to implement some sort of translating a nested list into a mptt list. I know, that in this format it's useless, but nested lists can be easily changed with a classes childs or anything else.
The code I have is:
tree = [[1,[[11,[111, 112, 113]],[12,]]],[2,[[21,[[211,[2111,]],]],]]]
class node():
def __init__(self, value, lft):
self.value = value
self.lft = lft
def add_right(self, rgt):
self.rgt = rgt
def __str__(self):
return "%s | %s | %s" %(self.value, self.lft, self.rgt)
def numerate(table, tree, counter):
for item in tree:
if type(item) == type(1):
table.append(node(item, counter))
index = len(table)
counter += 1
else:
table.append(node(item[0], counter))
index = len(table)
counter += 1
if len(item) > 1:
(table, counter) = numerate(table, item[1], counter)
table[index-1].add_right(counter)
return (table, counter)
table = numerate([], tree, 0)[0]
for item in table:
print item
But the result is:
1 | 0 | 6
11 | 1 | 5
111 | 2 | 3
112 | 3 | 4
113 | 4 | 5
12 | 5 | 6
2 | 6 | 10
21 | 7 | 10
211 | 8 | 10
2111 | 9 | 10
I see there is something not ok with the right value in recursion. I think such a format in python might be sometimes useful, so it would be nice to have some code for it already written.
The problem has been solved by adding a global iterator.
If someone is interested, that's the new numerate function, which actually works fine.
global_iterator = 0
def numerate(table, tree):
global global_iterator
for item in tree:
global_iterator += 1
if type(item) == type(1):
table.append(node(item, global_iterator))
index = len(table)
else:
table.append(node(item[0], global_iterator))
index = len(table)
if len(item) > 1:
table.append(numerate(table, item[1]))
global_iterator += 1
table[index-1].add_right(global_iterator)
return table
table = numerate([], tree)
The node() does not change.