Python Bugs

[Guest]

Here I am once again asking for your programming help.

 

I have no idea what's causing this bug but my code is trying to access None type objects.

 

Story Time:

I'm working on Breadth Search & recursive search with Python. I figured that part out. Right now I have some data type errors or something.

I'm used to C# where data types are explicitly stated so idk if I messed up mixing types.

 

Goal of program:

Find all nodes in the graph starting from Node 1.

 

I have 2 data structures.
"tree" which holds a series of "Node" which are outlined in the Node Class containing a value, the value of the Left Node & the value of the Right Node.

"output" is the second structure. This stores all the nodes found in the order they're found. There should be no duplicates as if a node is found, you shouldn't say you've found it again.

 

The graph is represented like so:

Spoiler

Node 1 has 2 & 3.

Node 2 has 4 & 5.

Node 3 has 4 & 5.

Node 4 has 5.
Node 5 has 1.

 

As some nodes have only 1 "child" I standardized that right nodes would be the only ones that can be None. Therefore, every Left Node should contain a value.

 

And now I have an error saying a Left Node is of type none.

 

 

 

1

Spoiler

Note that Line numbers are not accurate to relevant code I present. All irrelevant code is completely bug free & not used in any way.

 

Traceback (most recent call last):
  File "F:/Documents/CTU/Python.py", line 217, in <module>
    main()
  File "F:/Documents/CTU/Python.py", line 82, in main
    BreadthSearch()
  File "F:/Documents/CTU/Python.py", line 98, in BreadthSearch
    BreadthCheck(val)
  File "F:/Documents/CTU/Python.py", line 129, in BreadthCheck
    print(left.GetNumber())
AttributeError: 'NoneType' object has no attribute 'GetNumber'

 

Program relevant code:

 

 

 

 

Spoiler

class Node():
    def __init__(self, number, left, right):
        self.number = number
        self.left = left
        self.right = right
    def GetNumber(self):
        return self.number
    def GetLeft(self):
        return self.left
    def GetRight(self):
        return self.right
        
tree = []

selectedDVDs = []

output = []

def main():

    CreateTree()
    for val in tree:
        print(val.GetNumber())
        print(val.GetLeft())
        print(val.GetRight())
        print ("\n \n Next MEME \n \n")
    while True:
        choice = DataCheck()
        if (choice == "1"):
            RecursiveSearch()
        if (choice == "2"):
            BreadthSearch()
        if (choice == "3"):
            ViewDVDs()
        if (choice == "4"):
            SelectDVDs()
        if (choice == "5"):
            ViewTotalAndAverageCosts(selectedDVDs)
        if (choice =="6"):
            ViewDVDSpecifics()

def BreadthSearch():

    for val in tree:
        if (val.GetNumber() == 1):
            Que.append(val)
            output.append(val)
            BreadthCheck(val)
            break
    for val in output:
        print (str(val.GetNumber()))

def FindNode(number):
    for val in tree:
        if (number == val.GetNumber):
            return val

def BreadthCheck(node):


    right = FindNode(node.GetRight())
    rightExists = False
    left = FindNode(node.GetLeft())
    leftExists = False

    for val in output:
        if right == val:
            rightExists = True
        if left == val:
            leftExists = True
        if (rightExists and leftExists) or (leftExists and right is None):
            break

    if (right is not None) and not rightExists:
        print(right.GetNumber())
        output.append(right)
        BreadthCheck(right)
    if not leftExists:
        print(left.GetNumber())
        output.append(left)
        BreadthCheck(left)

def RecursiveSearch():
    print ("void")

def DataCheck():
    print ("1. recursive search")
    print ("2. breadth search")


    return input("Enter your choice: ")

def CreateTree():
    tree.append(Node(1, 2, 3))
    tree.append(Node(2, 4, 5))
    tree.append(Node(3, 4, 5))
    tree.append(Node(4, 5, None))
    tree.append(Node(5, 1, None))

 

Complete copy/paste if you really want it. (Caution Language):

 

 

 

 

Spoiler

Now that you're here... can you really program without vulgar language?

# That stockholm syndrome I had for python...
# It has turned to contempt with the hidden
# variable types. I cannot declare types so...
# I have to just get fucked when I have a data type
# error.
from enum import Enum

class DVDType(Enum):
    Game = 1
    Word = 2
    Compiler = 3
    Spreadsheet = 4
    Dbase = 5
    Presentation = 6

class Node():
    def __init__(self, number, left, right):
        self.number = number
        self.left = left
        self.right = right
    def GetNumber(self):
        return self.number
    def GetLeft(self):
        return self.left
    def GetRight(self):
        return self.right
tree = []
root = None
currentNode = None

start = 0
end = 0
selectedDVDs = []

output = []
Que = []

def listValidDVDTypes():
    print (DVDType.Game)
    print (DVDType.Word)
    print (DVDType.Compiler)
    print (DVDType.Spreadsheet)
    print (DVDType.Dbase)
    print (DVDType.Presentation)


class DVD:
    def __init__(self, Name, Type, Cost):
        self.Name = Name
        self.Type = Type
        self.Cost = Cost

    def SetName (self, name):
        self.Name = name
    def SetType(self, type):
        self.Type = type

    def GetName(self):
        return self.Name
    def GetType(self):
        return self.Type
    def GetCost(self):
        return self.Cost

#class Manager(Employee):
#    def GetPay(self):
#        return self.Hours * 5

def main():

    CreateTree()
    for val in tree:
        print(val.GetNumber())
        print(val.GetLeft())
        print(val.GetRight())
        print ("\n \n Next MEME \n \n")
    while True:
        choice = DataCheck()
        if (choice == "1"):
            RecursiveSearch()
        if (choice == "2"):
            BreadthSearch()
        if (choice == "3"):
            ViewDVDs()
        if (choice == "4"):
            SelectDVDs()
        if (choice == "5"):
            ViewTotalAndAverageCosts(selectedDVDs)
        if (choice =="6"):
            ViewDVDSpecifics()

def BreadthSearch():

    for val in tree:
        if (val.GetNumber() == 1):
            Que.append(val)
            output.append(val)
            BreadthCheck(val)
            break
    for val in output:
        print (str(val.GetNumber()))

def FindNode(number):
    for val in tree:
        if (number == val.GetNumber):
            return val

def BreadthCheck(node):


    right = FindNode(node.GetRight())
    rightExists = False
    left = FindNode(node.GetLeft())
    leftExists = False

    for val in output:
        if right == val:
            rightExists = True
        if left == val:
            leftExists = True
        if (rightExists and leftExists) or (leftExists and right is None):
            break

    if (right is not None) and not rightExists:
        print(right.GetNumber())
        output.append(right)
        BreadthCheck(right)
    if not leftExists:
        print(left.GetNumber())
        output.append(left)
        BreadthCheck(left)

def RecursiveSearch():
    print ("void")

def DataCheck():
    print ("1. recursive search")
    print ("2. breadth search")


    return input("Enter your choice: ")

def CreateTree():
    tree.append(Node(1, 2, 3))
    tree.append(Node(2, 4, 5))
    tree.append(Node(3, 4, 5))
    tree.append(Node(4, 5, None))
    tree.append(Node(5, 1, None))

def ViewDVDs():
    for val in tree:
        print (str(val.GetName()))

def SelectDVDs():
    while True:
        dvdSelect = input("Enter DVD index to select. Enter x to exit.")
        if (dvdSelect == 'x'):
            return
        int(dvdSelect)
        for x in range(len(tree)):
            if (x == int(dvdSelect)):
                dvdAdd = tree[x]
                selectedDVDs.append(dvdAdd)

def ViewDVDSpecifics():
    while True:
        dvdSelect = input("Enter DVD index to view. Enter x to exit.")
        if (dvdSelect == 'x'):
            return
        int(dvdSelect)
        for x in range(len(tree)):
            if (x == int(dvdSelect)):
                print("name: " + str(tree[x].GetName()))
                print("cost: " + str(tree[x].GetCost()))
                print("Type: " + str(tree[x].GetType()))


def ViewTotalAndAverageCosts(passedList):
    dvdCount = len(passedList)
    totalCost = 0
    for val in passedList:
        totalCost = totalCost + val.GetCost()

    print ("total cost: " + str(totalCost))
    averageCost = totalCost / dvdCount
    print ("Average cost: " + str(averageCost))

def AddDVD():
    name = input("Name: ")
    cost = input("Cost: ")
    InvalidValue = True
    while InvalidValue:
        listValidDVDTypes()
        chosen = input("Enter a number for a dvd type: ")
        if (chosen == "1"):
            type = DVDType.Game
            InvalidValue = False
        if (chosen == "2"):
            type = DVDType.Word
            InvalidValue = False
        if (chosen == "3"):
            type = DVDType.Compiler
            InvalidValue = False
        if (chosen == "4"):
            type = DVDType.Spreadsheet
            InvalidValue = False
        if (chosen == "5"):
            type = DVDType.Dbase
            InvalidValue = False
        if (chosen == "6"):
            type = DVDType.Presentation
            InvalidValue = False

    tree.append(DVD(name, type, cost))


main()

 

 

I tried viewing & reviewing code as I solved a previous bug in this program by reviewing code myself. I tried googling. I tried using my school's learning centre for them to tell me the best way to use the tutor centre is to not use the tutor centre & I even joined the Python Discord to ask & they either didn't want to help or couldn't. As per most of my questions I really do try as much as I can to solve it on my own & end up deleting hour long writing of a thread before I find the problem in 1 second but this time I really cannot figure it out.

You are my only hope.

 

I love you.

[Garry Motorway]

Your FindNode function on line 105 is comparing number to the method GetNumber. You need to call it!

def FindNode(number):
    for val in tree:
        if (number == val.GetNumber):
            return val

should be

def FindNode(number):
    for val in tree:
        if (number == val.GetNumber()):
            return val

 

[Guest]

19 minutes ago, Garry Motorway said:

Your FindNode function on line 105 is comparing number to the method GetNumber. You need to call it!

def FindNode(number):
    for val in tree:
        if (number == val.GetNumber):
            return val

should be

def FindNode(number):
    for val in tree:
        if (number == val.GetNumber()):
            return val

 

Your first post is the best post ever.

 

Thank you so much! PyCharm didn't tell me this & I have no idea why. Thank you thank you!