class ExpTree:

def $\_\_$init$\_\_($self$,$ rootObj$)$:

self.key $=$ rootObj

self.leftChild $=$ None

self.rightChild $=$ None

def insertLeft$($self$,$ newNode$)$:

if self.leftChild is None:

self.leftChild $=$ ExpTree$($newNode$)$

else:

t $=$ ExpTree$($newNode$)$

t$.$leftChild $=$ self.leftChild

self.leftChild $=$ t

def insertRight$($self$,$ newNode$)$:

if self.rightChild is None:

self.rightChild $=$ ExpTree$($newNode$)$

else:

t $=$ ExpTree$($newNode$)$

t$.$rightChild $=$ self.rightChild

self.rightChild $=$ t

def getRightChild$($self$)$:

return self.rightChild

def getLeftChild$($self$)$:

return self.leftChild

def setRootVal$($self$,$ obj$)$:

self.key $=$ obj

def getRootVal$($self$)$:

return self.key

@staticmethod

def make$\_$tree$($postfix$\_$expression$)$:

if isinstance$($postfix$\_$expression, str$)$:

tokens $=$ postfix$\_$expression.split$()$

elif isinstance$($postfix$\_$expression, list$)$:

tokens $=$ postfix$\_$expression

else:

raise ValueError$("$Invalid postfix$\_$expression type"$)$

stack $=$ Stack$()$

for token in tokens:

if $\text{'}.\text{'}$ in token:

stack.push$($ExpTree$($float$($token$)))$

elif token.isnumeric$()$:

stack.push$($ExpTree$($int$($token$)))$

elif token in $\text{'}+-*/^\text{'}$:

if token $==\text{'}^\text{'}$:

if stack.size$()<mtext\; id="EditorElement\_30637"></mtext><mn\; id="EditorElement\_30638">2</mn>$:

raise ValueError$("$Invalid postfix$\_$expression"$)$

right$\_$tree $=$ stack.pop$()$

left$\_$tree $=$ stack.pop$()$

new$\_$tree $=$ ExpTree$($token$)$

new$\_$tree.insertLeft$($left$\_$tree$)$

new$\_$tree.insertRight$($right$\_$tree$)$

stack.push$($new$\_$tree$)$

else:

if stack.size$()<mtext\; id="EditorElement\_31051"></mtext><mn\; id="EditorElement\_31052">2</mn>$:

raise ValueError$("$Invalid postfix$\_$expression"$)$

right$\_$tree $=$ stack.pop$()$

left$\_$tree $=$ stack.pop$()$

new$\_$tree $=$ ExpTree$($token$)$

new$\_$tree.insertLeft$($left$\_$tree$)$

new$\_$tree.insertRight$($right$\_$tree$)$

stack.push$($new$\_$tree$)$

if stack.size$()!=1$:

raise ValueError$("$Invalid postfix$\_$expression"$)$

return stack.pop$()$

@staticmethod

def inorder$($tree$)$:

if tree:

if tree.leftChild and tree.rightChild:

return f$\text{'}(\{$ExpTree$.$inorder$($tree$.$leftChild$)\}\{$tree$.$key$\}\{$ExpTree$.$inorder$($tree$.$rightChild$)\})\text{'}$

else:

return tree.key

@staticmethod

def postorder$($tree$)$:

if tree:

if tree.leftChild and tree.rightChild:

return f$\text{'}\{$ExpTree$.$postorder$($tree$.$leftChild$)\}\{$ExpTree$.$postorder$($tree$.$rightChild$)\}\{$tree$.$key$\}\text{'}$

else:

return f$\text{'}\{$tree$.$key$\}\text{'}$

@staticmethod

def preorder$($tree$)$:

if tree:

if tree.leftChild and tree.rightChild:

return f$\text{'}\{$tree$.$key$\}\{$ExpTree$.$preorder$($tree$.$leftChild$)\}\{$ExpTree$.$preorder$($tree$.$rightChild$)\}\text{'}$

else:

return f$\text{'}\{$tree$.$key$\}\text{'}$

def evaluate$($self$)$:

if isinstance$($self$.$key, ExpTree$)$:

return self.key.evaluate$()$

elif isinstance$($self$.$key, int$)$ or isinstance$($self$.$key, float$)$:

return float$($self$.$key$)$

else:

left$\_$val $=$ self.leftChild.evaluate$()$ if self.leftChild else $0$

right$\_$val $=$ self.rightChild.evaluate$()$ if self.rightChild else $0$

if self.key $==\text{'}+\text{'}$:

return left$\_$val $+$ right$\_$val

elif self.key $==\text{'}-\text{'}$:

return left$\_$val $-$ right$\_$val

elif self.key $==\text{'}*\text{'}$:

return left$\_$val $*$ right$\_$val

elif self.key $==\text{'}/\text{'}$:

return left$\_$val $/$ right$\_$val

elif self.key $==\text{'}^\text{'}$:

return left$\_$val $**$ right$\_$val

def $\_\_$str$\_\_($self$)$:

if self.leftChild and self.rightChild:

return f$\text{'}(\{$str$($self$.$leftChild$)\}\{$self$.$key$\}\{$str$($self$.$rightChild$)\})\text{'}$

else:

return self.key

I dont understand how my code does not pass the exptree test conditions

# test an ExpTree

try:

postfix $=\text{'}523*+\text{'}.$split$()$

tree $=$ ExpTree.make$\_$tree$($postfix$)$

print$($str$($tree$))$

assert str$($tree$)==\text{'}(5+(2*3))\text{'}$

score$3+=2$

except Exception:

pass

try:

assert ExpTree.inorder$($tree$)==\text{'}(5+(2*3))\text{'}$

assert ExpTree.postorder$($tree$)==\text{'}523*+\text{'}$

assert ExpTree.preorder$($tree$)==\text{'}+5*23\text{'}$

score$3+=2$

except Exception:

pass

try:

assert ExpTree.evaluate$($tree$)==11\mathrm{.}0$

score$3+=2$

except Exception:

pass

try:

postfix $=\text{'}52+3*\text{'}.$split$()$

tree $=$ ExpTree.make$\_$tree$($postfix$)$

assert str$($tree$)==\text{'}((5+2)*3)\text{'}$

assert ExpTree.inorder$($tree$)==\text{'}((5+2)$