Portfolio Rebalancer

def rebalance_portfolio(holdings: dict, total_value: float = None) -> dict:
    """
    holdings: {'AssetName': {'current_value': 50000, 'target_pct': 60}}
    Returns buy/sell amounts needed
    """
    if total_value is None:
        total_value = sum(h['current_value'] for h in holdings.values())

    results = {}
    for name, h in holdings.items():
        current = h['current_value']
        target_pct = h['target_pct']
        current_pct = (current / total_value) * 100 if total_value > 0 else 0
        target_value = (target_pct / 100) * total_value
        diff = target_value - current
        results[name] = {
            'current': current,
            'current_pct': round(current_pct, 2),
            'target_pct': target_pct,
            'target_value': round(target_value, 2),
            'action': round(diff, 2),
            'action_type': 'BUY' if diff > 0 else 'SELL' if diff < 0 else 'HOLD'
        }
    return results

# Example
portfolio = {
    'US Stocks':      {'current_value': 50000, 'target_pct': 60},
    'Bonds':          {'current_value': 30000, 'target_pct': 30},
    'International':  {'current_value': 10000, 'target_pct': 10},
}
result = rebalance_portfolio(portfolio)
total = sum(h['current_value'] for h in portfolio.values())
print(f"Total Portfolio: ${total:,.0f}")
for name, r in result.items():
    action = "BUY" if r['action'] > 0 else "SELL"
    print(f"{name}: {r['current_pct']}% → {r['target_pct']}%  |  {action} ${abs(r['action']):,.0f}")