python - Self-defined class issue: AttributeError: 'xx' object has no attribute 'xx'

Question

I am working on a self-defined class to solve the problem, which is pretty common format in leetcode. The problem is as:

Path with Maximum Sum (hard) # Find the path with the maximum sum in a given binary tree. Write a function that returns the maximum sum. A path can be defined as a sequence of nodes between any two nodes and doesn’t necessarily pass through the root.

My approach is:

class Solution:
    def __inti__(self):
        self.maxSum = 0

    def sumMax(self, root):
        # self.maxSum = 0
        self.findSum(root)
        return self.maxSum

    def findSum(self, root):
        if not root:
            return 0
        l = self.findSum(root.left)
        r = self.findSum(root.right)
        tempMax = l + r + root.value
        if tempMax > self.maxSum:
            self.maxSum = tempMax
        # self.maxSum = max(self.maxSum, tempMax)
        return max(l, r) + root.value

class TreeNode:
    def __init__(self, _value):
        self.value = _value
        self.left, self.right, self.next = None, None, None

def main():
    root = TreeNode(1)
    root.left = TreeNode(2)
    root.right = TreeNode(3)
    root.left.left = TreeNode(4)
    root.right.left = TreeNode(5)
    root.right.right = TreeNode(6)
    print(Solution().sumMax(root))

    root = TreeNode(1)
    root.left = TreeNode(2)
    root.right = TreeNode(3)
    root.left.left = TreeNode(1)
    root.left.right = TreeNode(3)
    root.right.left = TreeNode(5)
    root.right.right = TreeNode(6)
    root.right.left.left = TreeNode(7)
    root.right.left.right = TreeNode(8)
    root.right.right.left = TreeNode(9)
    print(Solution().sumMax(root))
main()

which will return error message as:

Traceback (most recent call last):
  File "/Users/tairanye/PycharmProjects/tester/main.py", line 46, in <module>
    main()
  File "/Users/tairanye/PycharmProjects/tester/main.py", line 33, in main
    print(Solution().sumMax(root))
  File "/Users/tairanye/PycharmProjects/tester/main.py", line 7, in sumMax
    self.findSum(root)
  File "/Users/tairanye/PycharmProjects/tester/main.py", line 13, in findSum
    l = self.findSum(root.left)
  File "/Users/tairanye/PycharmProjects/tester/main.py", line 13, in findSum
    l = self.findSum(root.left)
  File "/Users/tairanye/PycharmProjects/tester/main.py", line 16, in findSum
    if tempMax > self.maxSum:
AttributeError: 'Solution' object has no attribute 'maxSum'

Process finished with exit code 1

I think I follow the correct fashion, but not sure why this error happened. I can fix this error by inserting self.maxSum = 0 in my sumMax function, but I am not sure why my previous approach is not working. The Python version is 3.8.

Thank you for your help in advance.

---

• Update:

---

The typo made this error. But I have further question. Why did Python accept the misspelled __inti__ without a notification. I don't think it has this command as default. Thanks.

question from:https://stackoverflow.com/questions/65713175/self-defined-class-issue-attributeerror-xx-object-has-no-attribute-xx

Answer 1

in line 2 you misspelled def __init__(self):

This might not fix your issue but that's the mistake I found.