Easy Money

Prices show up in club sales, bake sales, and split lunches. Formatting them by hand is where extra pennies and missing zeros sneak in. easy_money rounds to cents and prints a currency symbol for you.

A small real-world example

Imagine three friends sharing a $48 pizza, and the shop adds 8.5% tax first.

from py_simple import add_tax, format_money, split_bill

with_tax = add_tax(48, 8.5)
each = split_bill(with_tax, 3)

print(format_money(with_tax))
print(format_money(each))

Example output:

$52.08
$17.36

What happened?

add_tax() takes the price and a percent, then returns the total rounded to cents.

calculate_tip() calculates the tip amount to add based on a percentage.

split_bill() divides that total by the number of people and rounds each share to cents.

format_money() prints the result with a dollar sign and two decimal places. Pass another symbol, such as "€", when you need one.

Calculating tips and discounts

Use calculate_tip() to find the tip on a bill:

from py_simple import calculate_tip, format_money

tip = calculate_tip(50, 18)
print(format_money(tip))  # $9.00

Use calculate_discount() to find the price after subtracting a discount:

from py_simple import calculate_discount, format_money

sale_price = calculate_discount(100, 15)
print(format_money(sale_price))  # $85.00

Keep every cent when splitting a bill

Use split_bill_exact() when you need all the shares to add up to the full bill, even when it cannot be divided evenly:

from py_simple import split_bill_exact

shares = split_bill_exact("10.00", 3)
print(shares)  # [Decimal('3.34'), Decimal('3.33'), Decimal('3.33')]
print(sum(shares))  # 10.00

It returns one Decimal per person, each with two decimal places. The total is rounded once to cents using ROUND_HALF_UP, then leftover cents go to the first shares. For example, "0.015" shared by two people becomes [Decimal('0.01'), Decimal('0.01')]. Refunds follow the same allocation: split_bill_exact(-10, 3) gives -3.34, -3.33, -3.33. Zero shares are Decimal('0.00'), including when a negative amount rounds to zero.

The amount may be an integer, float, numeric string or Decimal. Floats are converted through their string representation; strings or Decimal values are useful when entering exact amounts. Non-finite amounts and invalid inputs raise EasyMoneyError. The number of people must be a positive integer, excluding booleans. Amounts must be representable to cents in the current Decimal context; precision or rounding-trap failures also raise EasyMoneyError.

split_bill() keeps its existing behavior: it returns one rounded share, so split_bill(10, 3) is still Decimal('3.33').

Why use these helpers?

Float math can print 17.359999999 when you only wanted $17.36. These helpers use decimal rounding, so the number you show someone is the number you calculated.