Find Mode in Binary Search Tree LeetCode solution in Python

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class Solution:
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    def findMode(self, root):
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        curr_node = root
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        result = []
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        curr_streak = 0
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        curr_num = float("inf")
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        max_streak = 0
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        while curr_node:
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            if curr_node.left:
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                neighbor = curr_node.left
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                while neighbor.right is not None:
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                    neighbor = neighbor.right
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                neighbor.right = curr_node
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                tmp = curr_node.left
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                curr_node.left = None
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                curr_node = tmp
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            else:
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                # since we deleted the left pointer when we were done processing in the previous if-block,
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                # we know that we only reach this else case
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                # if we've already processed this node.
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                # Therefore, do the value processing here
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                # and move to the right neighbor afterward
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                if curr_node.val == curr_num:
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                    curr_streak += 1
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                else:
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                    curr_streak = 0
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                    curr_num = curr_node.val
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                if curr_streak == max_streak:
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                    result.append(curr_num)
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                elif curr_streak > max_streak:
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                    max_streak = curr_streak
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                    result = [curr_num]
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                curr_node = curr_node.right
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        return result