Q:

call a class function that calls another class function

if I have a class that calls that has a function that calls other functions written within the class, how can I make that work with multiple objects.  for example 
class MyClass:

    def __init__(self):
        self.a = []

    def do_somthing(self):
        self.a.append(5)
        print(self.a)

    def do_somthing_else(self):
        self.a.append(10)
        print(self.a)

    def do_both(self):
        do_somthing()
        do_somthing_else()

obj_one = MyClass()
obj_two = MyClass()
obj_one.do_both()
obj_two.do_both()

I understand how to make that work with one object, but how would I make that work with both objects
import itertools
class Financial_journal:

    def __init__(self):
        self.date = []
        self.expense = []
        self.amount_spent = []
        self.ballance = [100]
#this func has not been tested      
    def main_menu(self):
        entry =input("Enter the corresponding number:\n1.  Add an expense\n2.  change an entry\n 3.Review journal\n4.  Exit program").lower()
        if entry == "1":
            journal_one.add_expense()
        if entry == "3":
            pass
        if entry == "4":
            pass

    def add_name(self):
        pass

    def display_journal(self):
        entry_num = 0
        for d, e, r, b in itertools.zip_longest(self.date, self.expense, self.amount_spent, self.ballance):
            entry_num += 1
            print("\nentry:", entry_num, "date:" , d, "expense:" , e, "amount spent:" , r,"ballance:", b)

#checks that all lists are not missing data
    def missing_data(self):
#prompts user to edit missing dates
        for index, entry in enumerate(self.date):
            if entry == "None":
                journal_one.display_journal()

                item = input("\nthe date of the expense on entry {}, if you know the date enter it, if you do not, press continue and enter the date when it is discovered. ".format(index +1)).capitalize()
                if item == "continue":
                    journal_one.display_journal()
                else:
                    self.date[index] = item
                    print("Your journal was updated.") 
#prompts user to edit missing expenses
        for index, entry in enumerate(self.expense):
            if entry  == "None":
                journal_one.display_journal()

                item = input("\nthere was no expense on entry {}, if you know the item was purchased, enter it, if you do not, press continue and enter the expense when it is discovered. ".format(index +1)).capitalize()
                if item == "continue":
                    journal_one.display_journal()
                else:
                    self.expense[index] = item
                    print("Your journal was updated.") 
#promts user to add missing amounts spent
        for index, entry in enumerate(self.amount_spent):
            if entry  == "None":
                journal_one.display_journal()

                item = int(input("\nthe amount that was spent on entry {} is missing, if you know the amount that was spent, enter it, if you do not, press continue and enter the amount when it is discovered. ".format(index +1)))
                if item == "continue":
                    journal_one.display_journal()
                else:       
                    self.amount_spent[index] = int(item)
                    self.ballance[index] = self.ballance[index] - sum(self.amount_spent)
                    print("Your journal was updated.\n")
        journal_one.display_journal()

    def add_expense(self):
        journal_one.missing_data()
        self.date.append('None')
        self.expense.append("None")
        self.amount_spent.append(0)
        self.ballance.append((self.ballance[-1]))
        entry = input("\nenter the date the purchase was made. ") .capitalize()
        if entry ! = "Continue":
            self.date[-1] = (entry) 
        entry = input("were was the purchase made? ") .capitalize()
        if entry ! = "Continue":
            self.expense[-1] = (entry)
        entry = input("enter the amount of money that was spent. ") .capitalize()
        if entry ! = "Continue":
            self.amount_spent[-1] = int((entry))
        self.ballance[-1] = self.ballance[-1] - (self.amount_spent[-1])
        journal_one.display_journal()

journal_one = Financial_journal()
journal_one.add_expense()

add_expense() calls missing_data() and display_journal(), and missing_data() calls display_journal.  I realized the way I wrote it will not work with multiple objects. 

A:

You issue is that you are referencing the specific class instance you made within the class itself.  Instead, you should replace all instances of journal_one that are INSIDE the Financial_journal class with self.  This will call each of the following methods on the same object that you called add_expense() originally. 
Let me know if this makes sense, or if you need me to explain further.