added python 3.9 support - removed deprecated ElementTree features

Author: victor-ru

markdown/treeprocessors.py

@@ -121,7 +121,7 @@ def __processElementText(self, node, subnode, isText=True):
         childResult = self.__processPlaceholders(text, subnode)
 
         if not isText and node is not subnode:
-            pos = node.getchildren().index(subnode)
+            pos = list(node).index(subnode)
             node.remove(subnode)
         else:
             pos = 0
@@ -169,7 +169,7 @@ def linkText(text):
                         linkText(text)
 
                     if not isString(node): # it's Element
-                        for child in [node] + node.getchildren():
+                        for child in [node] + list(node):
                             if child.tail:
                                 if child.tail.strip():
                                     self.__processElementText(node, child, False)
@@ -224,7 +224,7 @@ def __applyPattern(self, pattern, data, patternIndex, startIndex=0):
         if not isString(node):
             if not isinstance(node.text, markdown.AtomicString):
                 # We need to process current node too
-                for child in [node] + node.getchildren():
+                for child in [node] + list(node):
                     if not isString(node):
                         if child.text:
                             child.text = self.__handleInline(child.text,
@@ -263,7 +263,7 @@ def run(self, tree):
         while stack:
             currElement = stack.pop()
             insertQueue = []
-            for child in currElement.getchildren():
+            for child in list(currElement):
                 if child.text and not isinstance(child.text, markdown.AtomicString):
                     text = child.text
                     child.text = None
@@ -272,7 +272,7 @@ def run(self, tree):
                     stack += lst
                     insertQueue.append((child, lst))
 
-                if child.getchildren():
+                if len(list(child)) > 0:
                     stack.append(child)
 
             for element, lst in insertQueue:
@@ -321,7 +321,7 @@ def run(self, root):
         self._prettifyETree(root)
         # Do <br />'s seperately as they are often in the middle of
         # inline content and missed by _prettifyETree.
-        brs = root.getiterator('br')
+        brs = root.iter('br')
         for br in brs:
             if not br.tail or not br.tail.strip():
                 br.tail = '\n'