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NameError: name 'self' is not defined - Printable Version

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NameError: name 'self' is not defined - walter - May-18-2022

Hi guys,
i am a newbie in Python. I have a problem with an OOP issue. This is my code 

class Solution:
  def __init__(self):  
      self.head = None

    def addTwoNumbers(self, lista1, lista2):
        carry = 0 
        Current1 = lista1.head
        Current2 = lista2.head
        ResultCurrent = self.head
        while (Current1.next != None and Current2.next != None ):
            if (Current1.data)+(Current2.data) > 10:
                datanew = Current1.data + Current2.data - 10 + carry
                carry = 1 
                ResultCurrent.insert(datanew)
            else:
                datanew = Current1.data + Current2.data + carry
                ResultCurrent.insert(datanew)
                carry = 0 
            Current1 = Current1.next
            Current2 = Current2.next     
            ResultCurrent = ResultCurrent.next
Follow the main:
def main():
    LL1 = LinkedList()
    LL1.insert(3)
    LL1.insert(4)
    LL1.insert(5)
    LL1.printLL()

    LL2 = LinkedList()
    LL2.insert(6)
    LL2.insert(7)
    LL2.insert(8)
    LL2.printLL()

    result = Solution()
    result.addTwoNumbers(self, LL1, LL2)
    result.printListLinked()
When i try to run this code i have an errore regarding the first argument of method of Solution class addTwoNumbers.

Thanks to community for your help.

Walter

RE: NameError: name 'self' is not defined - walter - May-18-2022

(May-18-2022, 02:31 PM)walter Wrote: Hi guys,
i am a newbie in Python. I have a problem with an OOP issue. This is my code

class Solution:
def __init__(self):
self.head = None

def addTwoNumbers(self, lista1, lista2):
carry = 0
Current1 = lista1.head
Current2 = lista2.head
ResultCurrent = self.head
while (Current1.next != None and Current2.next != None ):
if (Current1.data)+(Current2.data) > 10:
datanew = Current1.data + Current2.data - 10 + carry
carry = 1
ResultCurrent.insert(datanew)
else:
datanew = Current1.data + Current2.data + carry
ResultCurrent.insert(datanew)
carry = 0
Current1 = Current1.next
Current2 = Current2.next
ResultCurrent = ResultCurrent.next

Follow the main:
def main():
LL1 = LinkedList()
LL1.insert(3)
LL1.insert(4)
LL1.insert(5)
LL1.printLL()

LL2 = LinkedList()
LL2.insert(6)
LL2.insert(7)
LL2.insert(8)
LL2.printLL()

result = Solution()
result.addTwoNumbers(self, LL1, LL2)
result.printListLinked()

When i try to run this code i have an errore regarding the first argument of method of Solution class addTwoNumbers.

Thanks to community for your help.

Walter


RE: NameError: name 'self' is not defined - walter - May-18-2022

(May-18-2022, 02:31 PM)walter Wrote: Hi guys,
i am a newbie in Python. I have a problem with an OOP issue. This is my code

class Solution:
def __init__(self):
self.head = None

def addTwoNumbers(self, lista1, lista2):
carry = 0
Current1 = lista1.head
Current2 = lista2.head
ResultCurrent = self.head
while (Current1.next != None and Current2.next != None ):
if (Current1.data)+(Current2.data) > 10:
datanew = Current1.data + Current2.data - 10 + carry
carry = 1
ResultCurrent.insert(datanew)
else:
datanew = Current1.data + Current2.data + carry
ResultCurrent.insert(datanew)
carry = 0
Current1 = Current1.next
Current2 = Current2.next
ResultCurrent = ResultCurrent.next

Follow the main:
def main():
LL1 = LinkedList()
LL1.insert(3)
LL1.insert(4)
LL1.insert(5)
LL1.printLL()

LL2 = LinkedList()
LL2.insert(6)
LL2.insert(7)
LL2.insert(8)
LL2.printLL()

result = Solution()
result.addTwoNumbers(self, LL1, LL2)
result.printListLinked()

When i try to run this code i have an errore regarding the first argument of method of Solution class addTwoNumbers.

Thanks to community for your help.

Walter


RE: NameError: name 'self' is not defined - Axel_Erfurt - May-18-2022

Please use the button insert python to insert your code.

RE: NameError: name 'self' is not defined - walter - May-19-2022

Hi Axel,
i have upload the entire code. I try to search in the web the explanation but i did't understand. I don't quite understand the use of the self in un a class method. I couldn't even solve this simple code.
Walter

RE: NameError: name 'self' is not defined - Axel_Erfurt - May-19-2022

I mean the insert python here.

RE: NameError: name 'self' is not defined - walter - May-19-2022

Hi Axel,
i am so sorry but i don't see any button on my browser to insert my python code.
Walter

RE: NameError: name 'self' is not defined - Axel_Erfurt - May-19-2022

Did you not see the python button in the reply window?

[Image: python-logo.png]

RE: NameError: name 'self' is not defined - walter - May-19-2022

Hi Alex,
finally i see the botton Smile . So finally i can upload my code. 
   # A single node of a singly linked list
class Node:
  # constructor
  def __init__(self, data = None, next=None): 
    self.data = data
    self.next = next

# A Linked List class with a single head node
class LinkedList:
  def __init__(self):  
    self.head = None
  
  # insertion method for the linked list
  def insert(self, data):
    newNode = Node(data)
    if(self.head):
      current = self.head
      while(current.next):
        current = current.next
      current.next = newNode
    else:
      self.head = newNode
  
  # print method for the linked list
  def printLL(self):
    current = self.head
    while(current):
      print(current.data)
      current = current.next

class Solution:
  def __init__(self):  
    self.head = None

# insertion method for the linked list
  def insert(self, data):
    newNode = Node(data)
    if(self.head):
      current = self.head
      while(current.next):
        current = current.next
      current.next = newNode
    else:
      self.head = newNode

# print method for the linked list
  def printLinkedList(self):
    current = self.head
    while(current):
      print(current.data)
      current = current.next

  def addTwoNumbers(self, lista1, lista2):
    carry = 0
    Current1 = lista1.head
    Current2 = lista2.head
    ResultCurrent = self.head
    while (Current1.next != None and Current2.next != None ):
      if (Current1.data)+(Current2.data) > 10:
        datanew = Current1.data + Current2.data - 10 + carry
        carry = 1
        ResultCurrent.insert(datanew)
    else:
        datanew = Current1.data + Current2.data + carry
        ResultCurrent.insert(datanew)
        carry = 0
        Current1 = Current1.next
        Current2 = Current2.next
        ResultCurrent = ResultCurrent.next

def main():
    LL1 = LinkedList()
    LL1.insert(3)
    LL1.insert(4)
    LL1.insert(5)
    LL1.printLL()

    LL2 = LinkedList()
    LL2.insert(6)
    LL2.insert(7)
    LL2.insert(8)
    LL2.printLL()

    result = Solution()
    result.addTwoNumbers(self, LL1, LL2)
    result.printLinkedList()

if __name__ == "__main__":
    main()
The follow error

File "c:\PYTHON\000-WEB SITE LEETCODE\SommaDidueNumeri\SommaDueNumeri.py", line 89, in <module>
main()
File "c:\PYTHON\000-WEB SITE LEETCODE\SommaDidueNumeri\SommaDueNumeri.py", line 85, in main
result.addTwoNumbers(self, LL1, LL2)
NameError: name 'self' is not defined
PS C:\Users\wrieppi>

Help me to write the class solution in a better way. And explain me my error.

Walter

RE: NameError: name 'self' is not defined - Axel_Erfurt - May-19-2022

remove self

result.addTwoNumbers(LL1, LL2)

and you get

Output:
3
4
5
6
7
8