simple_budget_tracker/budget.py

#!/usr/bin/python3
import datetime
from decimal import *
from settings import DATA
from prettytable import PrettyTable

TWOPLACES = Decimal(10) ** -2

def daterange(start_date, end_date):
    for n in range(int ((end_date - start_date).days)):
        yield start_date + datetime.timedelta(n)

class PayPeriod:
    def __init__(self, calculate=False):
        self.bills = []
        self.expenses = DATA.get('expenses')
        self.delta = None
        self.beginning = None
        self.end = None
        self.total_bills = None
        self.money_left = None
        self.total_expenses = None
        if calculate:
            self.calculate_budget()

    def lookup_bills(self):
        if not self.beginning or not self.end:
            self.current_pay_period()
        bill_data = DATA.get('bills')

        for day in daterange(self.beginning, self.end):
            x = bill_data.get(day.day)
            if x:
                for bill in x:
                    self.bills.append(bill)

    def pay_period_delta(self):
        period = DATA.get('pay_period')
        if not period:
            raise Error

        unit = period.get('unit')
        value = period.get('value')

        if unit == 'week':
            self.delta = datetime.timedelta(weeks=value)
        elif unit == 'day':
            self.delta = datetime.timedelta(days=value)
        elif unit == 'month':
            self.delta = value
        else:
            raise Error

    def current_pay_period(self):
        self.find_pay_period(datetime.date.today())

    def next_pay_period(self):
        if self.delta == None:
            self.pay_period_delta()

        next_period = PayPeriod()
        next_period.find_pay_period(datetime.date.today() + self.delta)
        next_period.calculate_budget()

        return next_period

    def find_pay_period(self, date):
        if self.delta == None:
            self.pay_period_delta()

        pay_date_str = DATA.get('pay_date')
        if not pay_date_str:
            raise Error

        pay_period = DATA.get('pay_period')
        if not pay_period:
            raise Error

        pay_date_list = pay_date_str.split('/')
        pay_date = datetime.date(int(pay_date_list[0]), int(pay_date_list[1]), int(pay_date_list[2]))

        beginning = pay_date
        end = pay_date

        while date > end:
            beginning = end
            end += self.delta

        self.beginning = beginning
        self.end = end

    def calculate_budget(self):
        if not self.bills:
            self.lookup_bills()

        self.total_bills = Decimal(0)
        for bill in self.bills:
            self.total_bills += bill.get('amt')

        self.total_expenses = Decimal(0)
        for expense in self.expenses:
            self.total_expenses += expense.get('amt')

        self.money_left = DATA.get("pay_amount") - self.total_bills - self.total_expenses

    def print_budget(self):
        if not self.total_bills:
            self.calculate_budget()

        print("\nBills")
        print("***************************")
        bills_table = PrettyTable(["Description", "Amount"])
        bills_table.align["Amount"] = "r"
        for bill in self.bills:
            bills_table.add_row([bill.get('desc'), bill.get('amt').quantize(TWOPLACES)])
        bills_table.add_row(["----------", "-----"])
        bills_table.add_row(["Total", self.total_bills.quantize(TWOPLACES)])
        print(bills_table)

        print("\nExpenses")
        print("***************************")
        expenses_table = PrettyTable(["Description", "Amount"])
        expenses_table.align["Amount"] = "r"
        for expense in self.expenses:
            expenses_table.add_row([expense.get('desc'), expense.get('amt').quantize(TWOPLACES)])
        expenses_table.add_row(["----------", "-----"])
        expenses_table.add_row(["Total", self.total_expenses.quantize(TWOPLACES)])
        print(expenses_table)

        print("\nTotals")
        print("***************************")
        print("Expenses Total: " + str(self.total_expenses.quantize(TWOPLACES)))
        print("Money After Bills + Expenses: " + str(self.money_left.quantize(TWOPLACES)))
        next_period = self.next_pay_period()
        money_left_next = next_period.money_left
        print("Money After Bills + Expenses Next: " + str(money_left_next.quantize(TWOPLACES)))

        if money_left_next <= 0:
            print("Not enough money left next paycheck!! Expenses being rolled together!")
            self.expenses += next_period.expenses
            self.calculate_budget()
            self.money_left = self.money_left + money_left_next + next_period.total_expenses
            print("Money left after combining: " + str(self.money_left.quantize(TWOPLACES)))

        print("\nPercent Expenses")
        print("***************************")

        total_perc_expenses = Decimal(0)
        perc_expenses = PrettyTable(["Description", "Amount"])
        perc_expenses.align["Amount"] = "r"
        for perc_expense in DATA.get("perc_expenses", []):
            amt = perc_expense.get('perc') * self.money_left
            total_perc_expenses += amt
            perc_expenses.add_row([perc_expense.get('desc'), amt.quantize(TWOPLACES)])
        perc_expenses.add_row(["----------", "-----"])
        perc_expenses.add_row(["Total", total_perc_expenses.quantize(TWOPLACES)])
        print(perc_expenses)

        money_left_perc = self.money_left - total_perc_expenses

        print("\nAllowances")
        print("***************************")
        allowance_table = PrettyTable(["Description", "Amount"])
        allowance_table.align["Amount"] = "r"
        for allowance in DATA.get("allowances", []):
            amt = allowance.get('perc') * money_left_perc
            allowance_table.add_row([allowance.get('desc'), amt.quantize(TWOPLACES)])
        print(allowance_table)

pay_period = PayPeriod()
pay_period.print_budget()