Corporate Lease vs Buy (CapEx Loan) NPV & Depreciation Tax Shield Analyzer in Python

import numpy as np

def compare_lease_vs_buy(asset_cost, lease_annual, dep_rate, tax_rate, post_tax_cost_of_debt, years):
    # 1. Present Value of Leasing
    after_tax_lease = lease_annual * (1 - tax_rate)
    pv_lease = sum(after_tax_lease / ((1 + post_tax_cost_of_debt) ** t) for t in range(1, years + 1))
    
    # 2. Present Value of Buying (with WDV Depreciation Tax Shield)
    wdv = asset_cost
    pv_tax_shields = 0.0
    for t in range(1, years + 1):
        dep = wdv * dep_rate
        tax_shield = dep * tax_rate
        pv_tax_shields += tax_shield / ((1 + post_tax_cost_of_debt) ** t)
        wdv -= dep
    pv_buy = asset_cost - pv_tax_shields
    return {'PV_Cost_Lease': round(pv_lease, 2), 'PV_Cost_Buy': round(pv_buy, 2), 'Recommended_Option': 'LEASE' if pv_lease < pv_buy else 'BUY_CAPEX'}