Modifying Class File/ Name-Mangling

[CWillis105]

Python 3.9.5
Mac OS

Hi All,

I am working on an assignment and could really use some help. It involves two different files (Customer.py and main.py). The instructions I don't understand are Steps 2 and 3.

This is what I have tried: Every variable in customer.py uses the _variable notation (2 underscores) which I think protects others from assigning something to them. It seems to me that to retrieve the right value the main program would use myCustomer.getEmail() instead of myCustomer.Email but they don't. I believe the answer lies in using the name mangling prevention technique with double underscores for the variables. I have played with this and I'm not getting anywhere.

THESE ARE THE STEPS I DON'T UNDERSTAND:

2) Modify the Class File to take advantage of Name Mangling for the Email Attribute so that the property cannot be modified directly by a consumer of the class.

3) add at least 1 additional attribute to the class and make sure your new attribute takes advantage of Name Mangling.

THIS IS THE CODE (there are two files copies and pasted, customer.py and main.py.

Customer.py file

class Customer:
  __Name=""
  __DateOfBirth="1/1/1900"
  __AccountNumber = "Unassigned"
  #note no name mangling on Email attribute (Accessible from outside)
  Email = "[email protected]"

  #constructor
  def __init__(self,Name,DOB,AccountNum,Email):
    self.__Name = Name
    self.__DateOfBirth=DOB
    self.__AccountNumber = AccountNum
    self.Email = Email

  def getName(self):
    return self.__Name

  def getDOB(self):
    return self.__DateOfBirth

  def getAccountNumber(self):
    return self.__AccountNumber

  def getEmail(self):
    return self.Email

  def setName(self,newName):
    self.__Name = newName

  def setDOB(self,newDOB):
    self.__DateOfBirth = newDOB

  def setAccountNumber(self,newAcctNum):
    self.__AccountNumber = newAcctNum

  def setEmail(self,newEmail):
    self.Email = newEmail


  def __del__(self):
    print("Object instance successfully removed")

main.py file

from Customer import Customer


def Main():
  myCustomer = Customer("Bob","12/12/1982","1090-332","[email protected]")
  print(myCustomer.getName() + " " + str(myCustomer.getDOB()) + " " + str(myCustomer.getAccountNumber()) + " " + myCustomer.getEmail())


  myCustomer.Email = "THIS IS A BAD EMAIL ADDRESS" #WORKS
  print(myCustomer.getName() + " " + myCustomer.getDOB() + " " + myCustomer.getAccountNumber() + " " + myCustomer.Email)
  
  myCustomer.AccountNumber = "BAD Account Number" #Doesnt Work...OR DOES IT ?
  print(myCustomer.getAccountNumber()) #OLD Account Number still in tact

  print(myCustomer.AccountNumber)

  #python can be confusing in this regard. BUT our internal data IS still safe Except for the Email that does NOT use Name Mangling
  print(myCustomer.getName() + " " + myCustomer.getDOB() + " " + myCustomer.getAccountNumber() + " " + myCustomer.Email)





Main()

Larz60+ write Jun-10-2021, 01:54 AM:
Please post all code, output and errors (it it's entirety) between their respective tags. Refer to BBCode help topic on how to post. Use the "Preview Post" button to make sure the code is presented as you expect before hitting the "Post Reply/Thread" button.

Fixed for you this time. Please use bbcode tags on future posts.