income tax plotter

tax.py

import matplotlib.pyplot as plt
import numpy as np

def tax(income):
    income *= 1000

    tax = 0
    taxable = income

    # 0-2.5L - 0%
    if taxable < 250000:
        return 0

    # 2.5-5L - 5%
    taxable -= 250000
    if taxable >= 0:
        tax += min(taxable, 250000) * 0.05

    # 5-10L - 20%
    taxable -= 250000
    if taxable > 0:
        tax += min(taxable, 500000) * 0.20

    # >10L - 30%
    taxable -= 500000
    if taxable > 0:
        tax += taxable * 0.30

    # >1Cr - 12% surcharge (subject to marginal relief)
    if income > 10000000:
        if (income - 10000000) > ((tax * 1.12) - (tax * 1.1)):
            tax *= 1.12
        else:
            tax = tax * 1.1 + (income - 10000000)
    # >50L - 10% surcharge (subject to marginal relief)
    elif income > 5000000:
        if (income - 5000000) > (tax * 0.1):
            tax *= 1.1
        else:
            tax += (income - 5000000)

    # 3% edu cess
    tax *= 1.03

    return tax / 1000

t = np.arange(0, 12000, 1)
s = map(tax, t)
plt.plot(t, s)

plt.xlabel('income (1000s)')
plt.ylabel('tax (1000s)')
plt.show()