1 """ |
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2 Implements the tree containing pages and their metadata |
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3 """ |
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4 |
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5 from lib import tree_parse |
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6 |
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7 class PageTreeError (Exception) : |
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8 """ |
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9 Error parsing/loading the page tree |
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10 """ |
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11 |
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12 pass |
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13 |
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14 class PageInfo (object) : |
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15 """ |
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16 Contains metainformation about a page |
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17 """ |
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18 |
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19 def __init__ (self, parent, name, title, children=None) : |
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20 """ |
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21 Initialize, children defaults to empty list |
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22 """ |
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23 |
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24 # store |
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25 self.parent = parent |
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26 self.name = name |
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27 self.title = title |
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28 self.children = children if children else [] |
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29 |
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30 # no url get |
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31 self._url = None |
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32 |
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33 def set_parent (self, parent) : |
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34 """ |
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35 Set a parent where non was set before |
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36 """ |
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37 |
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38 assert self.parent is None |
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39 |
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40 self.parent = parent |
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41 |
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42 def add_child (self, child) : |
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43 """ |
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44 Add a PageInfo child |
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45 """ |
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46 |
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47 self.children.append(child) |
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48 |
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49 def get_child (self, name) : |
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50 """ |
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51 Look up a child by name, returning None if not found |
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52 """ |
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53 |
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54 return dict((c.name, c) for c in self.children).get(name) |
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55 |
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56 def get_ancestry (self) : |
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57 """ |
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58 Returns a list of this page's parents and the page itself, but not root |
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59 """ |
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60 |
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61 # collect in reverse order |
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62 ancestry = [] |
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63 |
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64 # starting from self |
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65 item = self |
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66 |
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67 # add all items, but not root |
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68 while item and item.parent : |
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69 ancestry.append(item) |
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70 |
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71 item = item.parent |
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72 |
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73 # reverse |
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74 ancestry.reverse() |
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75 |
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76 # done |
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77 return ancestry |
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78 |
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79 @property |
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80 def url (self) : |
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81 """ |
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82 Build this page's URL |
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83 """ |
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84 |
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85 # cached? |
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86 if self._url : |
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87 return self._url |
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88 |
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89 segments = [item.name for item in self.get_ancestry()] |
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90 |
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91 # add empty segment if dir |
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92 if self.children : |
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93 segments.append('') |
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94 |
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95 # join |
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96 url = '/'.join(segments) |
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97 |
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98 # cache |
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99 self._url = url |
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100 |
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101 # done |
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102 return url |
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103 |
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104 class PageTree (object) : |
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105 """ |
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106 The tree of pages, rooted at .root. |
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107 |
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108 Use load_page_tree to initialize the global page_tree instance, and then use that |
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109 """ |
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110 |
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111 def __init__ (self, path) : |
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112 """ |
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113 Loads the PageTree root from the given file |
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114 """ |
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115 |
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116 # store |
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117 self.path = path |
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118 |
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119 # load |
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120 self._load(path) |
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121 |
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122 def _load (self, path) : |
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123 """ |
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124 Processes the lines in the given file |
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125 """ |
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126 |
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127 # parse tree |
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128 tree = tree_parse.parse(path, ':') |
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129 |
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130 if not tree : |
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131 raise PageTreeError("No root node found") |
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132 |
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133 def _create_node (parent, item) : |
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134 """ |
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135 Creates and returns a PageInfo from the given parent node and (line_number, line, children) tuple item |
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136 """ |
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137 |
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138 # unpack |
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139 line_number, line, children = item |
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140 |
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141 # parse line |
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142 url = title = None |
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143 |
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144 try : |
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145 url, title = line.split(':') |
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146 |
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147 except : |
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148 raise PageTreeError("Invalid line: %s:%d: %r" % (path, line_number, line)) |
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149 |
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150 # remove whitespace |
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151 url = url.strip() |
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152 title = title.strip() |
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153 |
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154 # create PageInfo |
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155 node = PageInfo(parent, url, title) |
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156 |
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157 # set node children |
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158 node.children = [ |
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159 _create_node(node, child_item) for child_item in children |
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160 ] |
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161 |
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162 # return |
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163 return node |
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164 |
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165 # translate |
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166 self.root = _create_node(None, tree) |
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167 |
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168 # *evil cackle* |
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169 self.root.children.insert(0, self.root) |
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170 |
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171 def get_page (self, url) : |
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172 """ |
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173 Lookup the given page URL, and return the matching PageInfo object, or None, if not found |
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174 """ |
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175 |
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176 # start from root |
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177 node = self.root |
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178 |
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179 # traverse the object tree |
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180 for segment in url.split('/') : |
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181 if segment : |
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182 node = node.get_child(segment) |
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183 |
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184 if not node : |
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185 return None |
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186 |
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187 # return |
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188 return node |
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189 |
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190 def get_siblings (self, url) : |
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191 """ |
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192 Get the list of siblings for the given url, including the given page itself |
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193 """ |
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194 |
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195 # look up the page itself |
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196 page = self.get_page(url) |
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197 |
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198 # specialcase root/unknown node |
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199 if page and page.parent : |
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200 return page.parent.children |
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201 |
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202 else : |
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203 return self.root.children |
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204 |
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205 def dump (self) : |
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206 """ |
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207 Returns a string representation of the tree |
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208 """ |
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209 |
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210 def _print_node (indent, node) : |
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211 return '\n'.join('%s%s' % (' '*indent, line) for line in [ |
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212 "%-15s : %s" % (node.name, node.title) |
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213 ] + [ |
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214 _print_node(indent + 4, child) for child in node.children if child != node |
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215 ]) |
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216 |
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217 return _print_node(0, self.root) |
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218 |
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