order_target_percent.py

def order_target_percent(api, security, weight, order_type='market', time_in_force='day'):
    account = api.get_account()
    portfolio_value = float(account.portfolio_value)
    
    current_holdings = 0
    try:
        current_holdings = api.get_position(security).qty
    except alpaca_trade_api.rest.APIError:
        current_holdings = 0
    
    stock_price = api.get_barset(security, "minute", limit=2)[security][-1].c
    current_weight = (current_holdings * stock_price) / portfolio_value
    
    weight = weight - current_weight
    side = 'buy' if weight > 0 else 'sell'
    
    quantity = int((portfolio_value * abs(weight)) / stock_price)
    
    api.submit_order(security, quantity, side, order_type, time_in_force)