1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
from sqlalchemy.mapper import *
from sqlalchemy.schema import *
from sqlalchemy.sql import *
import sqlalchemy.util as util
import tables
import string, sys
"""a basic Adjacency List model tree."""
class NodeList(util.OrderedDict):
"""extends an Ordered Dictionary, which is just a dictionary that returns its keys and values
in order upon iteration. Adds functionality to automatically associate
the parent of a TreeNode with itself, upon append to the parent's list of child nodes."""
def __init__(self, parent):
util.OrderedDict.__init__(self)
self.parent = parent
def append(self, node):
node.parent = self.parent
self[node.name] = node
def __iter__(self):
return iter(self.values())
class TreeNode(object):
"""a rich Tree class which includes path-based operations"""
def __init__(self, name=None):
self.children = NodeList(self)
self.name = name
self.parent = None
self.id = None
self.parent_id = None
def append(self, node):
if isinstance(node, str):
self.children.append(TreeNode(node))
else:
self.children.append(node)
def __repr__(self):
return self._getstring(0, False)
def __str__(self):
return self._getstring(0, False)
def _getstring(self, level, expand = False):
s = (' ' * level) + "%s (%s,%s, %d)" % (self.name, self.id,self.parent_id,id(self)) + '\n'
if expand:
s += string.join([n._getstring(level+1, True) for n in self.children.values()], '')
return s
def print_nodes(self):
return self._getstring(0, True)
# define the mapper. we will make "convenient" property
# names vs. the more verbose names in the table definition
TreeNode.mapper=assignmapper(tables.trees, class_=TreeNode, properties=dict(
id=tables.trees.c.node_id,
name=tables.trees.c.node_name,
parent_id=tables.trees.c.parent_node_id,
root_id=tables.trees.c.root_node_id,
children=relation(TreeNode, primaryjoin=tables.trees.c.parent_node_id==tables.trees.c.node_id, foreignkey=tables.trees.c.parent_node_id, thiscol=tables.trees.c.node_id, lazy=True, uselist=True, private=True),
))
node2 = TreeNode('node2')
node2.append('subnode1')
node = TreeNode('rootnode')
node.append('node1')
node.append(node2)
node.append('node3')
node.children['node2'].append('subnode2')
print "\n\n\n----------------------------"
print "Created new tree structure:"
print "----------------------------"
print node.print_nodes()
print "\n\n\n----------------------------"
print "Committing:"
print "----------------------------"
objectstore.commit()
print "\n\n\n----------------------------"
print "Tree After Save:"
print "----------------------------"
print node.print_nodes()
node.append('node4')
node.children['node4'].append('subnode3')
node.children['node4'].append('subnode4')
node.children['node4'].children['subnode3'].append('subsubnode1')
del node.children['node1']
print "\n\n\n----------------------------"
print "Modified the tree"
print "(added node4, node4/subnode3, node4/subnode4,"
print "node4/subnode3/subsubnode1, deleted node1):"
print "----------------------------"
print node.print_nodes()
print "\n\n\n----------------------------"
print "Committing:"
print "----------------------------"
objectstore.commit()
#sys.exit()
print "\n\n\n----------------------------"
print "Tree After Save:"
print "----------------------------"
print node.print_nodes()
nodeid = node.id
print "\n\n\n----------------------------"
print "Clearing objectstore, selecting "
print "tree new where node_id=%d:" % nodeid
print "----------------------------"
objectstore.clear()
t = TreeNode.mapper.select(TreeNode.c.node_id==nodeid)[0]
print "\n\n\n----------------------------"
print "Full Tree:"
print "----------------------------"
print t.print_nodes()
print "\n\n\n----------------------------"
print "Marking root node as deleted"
print "and committing:"
print "----------------------------"
objectstore.delete(t)
objectstore.commit()
|
