[Python] Compute french taxes in euro

impot.py

#!/usr/bin/env python3
#
# Compute french taxes in euro.
#
# usage:
#   python3 impot.py <yearly_gross_salary>

TAXE_SLICES = [(9710, 0.14), (26818, 0.30), (71898, 0.41), (152260, 0.45)]

def get_taxe_amounts_per_slice():
    global TAXE_SLICES
    taxe_amounts_per_slice = [0]
    for slice_index in range(len(TAXE_SLICES) - 1):
        amount = TAXE_SLICES[slice_index + 1][0] - TAXE_SLICES[slice_index][0]
        taxe_amount = amount * (TAXE_SLICES[slice_index][1])
        taxe_amounts_per_slice.append(taxe_amount)
    return taxe_amounts_per_slice

def get_yearly_net_salary(yearly_net_salary):
    return yearly_net_salary * (1 - 0.23)

def get_category(yearly_net_salary):
    global TAXE_SLICES
    num_category = 0
    for taxe_slice, _ in TAXE_SLICES:
        if yearly_net_salary <= taxe_slice:
            break
        num_category += 1
    return num_category

def get_taxe_amount(yearly_net_salary):
    global TAXE_SLICES
    taxe_amount = 0
    taxe_amounts_per_slice = get_taxe_amounts_per_slice()
    num_category = get_category(yearly_net_salary)
    for category in range(num_category):
        taxe_amount += taxe_amounts_per_slice[category]
    amount = yearly_net_salary - TAXE_SLICES[num_category - 1][0]
    taxe_amount += amount * TAXE_SLICES[num_category - 1][1]
    return taxe_amount

def get_salary(yearly_net_salary, taxe_amount):
    return yearly_net_salary - taxe_amount

def get_salary_per_month(yearly_salary):
    return yearly_salary / 12

if __name__ == "__main__":
    import sys

    args = sys.argv[1:]
    yearly_gross_salary = int(args[0])
    print("yearly gross salary: {0:.2f}€".format(yearly_gross_salary))

    yearly_net_salary = get_yearly_net_salary(yearly_gross_salary)
    print("yearly net salary: {0:.2f}€".format(yearly_net_salary))

    monthly_net_salary = get_salary_per_month(yearly_net_salary)
    print("monthly net salary: {0:.2f}€".format(monthly_net_salary))

    taxe_amount = get_taxe_amount(yearly_net_salary)
    print("taxe amount: {0:.2f}€".format(taxe_amount))

    yearly_salary = get_salary(yearly_net_salary, taxe_amount)
    print("yearly salary: {0:.2f}€".format(yearly_salary))