def display_expense_by_month():
"""
Summarize all expesnses by month
:return: All expenses subtotal in last 12 months
:rtype: dict
"""
EM = ExpenseManager()
EM.from_csv(expense_csv)
return EM.by_month_expense()
def test_by_month_expense():
manager = ExpenseManager()
Expense1 = Expense(1, "Food", 50, "2020-04-29")
Expense2 = Expense(2, "School", 20, "2021-04-30")
Expense3 = Expense(3, "Food", 36.6, "2021-05-01")
Expense4 = Expense(4, "Family", 100, "2021-05-02")
Expense5 = Expense(5, "Family", 88.8, "2021-01-02")
Expense6 = Expense(6, "Health", 62, "2021-01-31")
# Add to the manager
manager.add_expense(Expense1)
manager.add_expense(Expense2)
manager.add_expense(Expense3)
manager.add_expense(Expense4)
manager.add_expense(Expense5)
manager.add_expense(Expense6)
assert manager.by_month_expense()["Apr"] == 20
assert manager.by_month_expense()["May"] == 136.6
assert manager.by_month_expense()["Jan"] == 150.8
