Я получаю ошибку атрибута, и я не понимаю, почему. Python

Question

Вот сообщение об ошибке:

line 68, in isValid 
    for symbol in (self.AllValidSymbols): 
AttributeError: 'ExpressionEvaluation' object has no attribute 'AllValidSymbols' 

Я не понимаю, потому что в моем коде (ниже) я intilized его иметь AllValidSymbols набор в список. Я знаю, что в коде есть больше проблем, я просто не понимаю эту ошибку.

class ExpressionEvaluation(): 
     stack = stack() 
     def __int__(self): 
     self.allinfixExpressions = [] 
     self.infixObj = InfixToPostfix() 
     self.operatorList = ['+', '-', '*', '/', '%', '^', '@'] 
     self.AllValidSymbols = ['(', ')', '{', '}', '[', ']', '+', '-', '*', 

     '/', '%','^', '@', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'] 



def getExpressionsFromFile(self, filename): 
    self.allinfixExpressions = [] 
    if (os.path.isfile(filename)): 
     infile = open(filename, 'r') 
     expr = infile.readline() 
     while (expr != ""):#file is not empty 
      expr = expr.strip() 
      expr = expr.replace(" ", "")#remove spaces 
      expr = expr.replace("//", "@")#remove spaces 
      expr = expr.replace("**", "^")#remove spaces 
      self.allinfixExpressions.append(expr) 
      expr = infile.readline()#get next expression 
     infile.close() 
     return True 
    else: 
     return False 
def doesNotMatch(self, left, right): 
    answer = False 
    if(left == '(' and right != ')'): 
     answer = True 
    elif (left == '[' and right != ']'): 
     answer = True 
    elif (left == '{' and right != '}'): 
     answer = True 

def isBalanced(self, expr): 
    balanced = True 
    index = 0 
    expr = expr.strip() 
    expr = expr.replace(" ", "") 
    while(index < len(expr) and balanced): 
     symbol = expr[index] 
     if(symbol in '([{'): 
      self.stack.push(symbol) 
     elif (symbol in ')]}'): 
      if(self.stack.is_empty()): 
       balanced = False 
      else: 
       item = self.stack.pop() 
       if (self.doesNotMatch(item, symbol)): 
        balanced = False 
     index += 1 
    if(balanced and self.stack.is_empty()): 
     return True 
    return False 

def removeSymbol(self, symbol, exprList): 
    n = exprList.count(symbol) 
    for i in range(n): 
     exprList.remove(elem) 
def isValid(self,expr): 
    exprList = list(expr) 
    for symbol in (self.AllValidSymbols): 
     self.removeSymbol(symbol, exprList) 
    exprList = list(infixList) 
    for elem in tempList: 
     if(elem.isdigit()): 
      self.removeElement(elem, PostfixList) 
    if(postfixList == []): 
     return True 
    else: 
     return False 
def evaluateExpressions(self): 
    # print(self.allinfixExpressions) 
    if (self.allinfixExpressions == []): #empty list 
     print("the input list is empty! there is nothing to evaluate.") 
    else: 
     for expr in self.allinfixExpressions: 
      balanced = self.isBalanced(expr) 
      valid = self.isValid(expr) 
      if (balanced and valid):#good to go 
       postfixlist = self.InfixToPostfix(expr) 
       postfixExpr = self.getPostfix(postfixlist) 
       result = self.evaluatePostfix(postfixlist) 
       self.printresult(expr, postfixList) 
      else: 
       print("not balanced or valid.") 


    def main(): 
    system = ExpressionEvaluation() 
    goodFile = system.getExpressionsFromFile('infixexpressions5.txt') 
    if(goodFile): 
     system.evaluateExpressions() 
    main() 

Answer 1

Это потому, что ваша инициализация не запуская, у вас есть опечатка в названии __init__ метода.