Close portion of trade and leave remainder to run

[CadeHalcyon]

Hi there, I have a simple problem, which is driving me crazy. I've simplified a scenario below... I want to:

• close 50% of long trade when price rises 5% above the trade entry price
• then move the stop loss to the entry price
• leave the rest of the trade to run until it hits the tp target of +10% set via self.buy(tp=price*1.10....)

The problem:

The trade will continue to reduce by 50% again and again after price moves 5% above entry price. Trade size will go from 1000 to 500 to 250 to 125 etc...

Question:

How do I only close out a portion of the trade once, please? In my mind, I want to somehow reference the size of the trade when it was first opened to create a condition for closing 50%, but trade.size in self.trades and position.size in self.position both get overwritten each time a portion of the trade is closed.

Grateful for any help! Simplified code below:

price = self.data.Close[-1]
if not self.position:
    self.buy(sl=price*0.98, size=1000, tp=price*1.10)
    
if self.position:
    for trade in self.trades:
        if trade.is_long:
            if price > (trade.entry_price * 1.05):     #want to close out half of position when first TP of +5% is hit
                self.position.close(portion=0.5)       #how to make this only happen once for each trade?
                trade.sl = trade.entry_price           #bring stop loss to entry and let remaining position ride until either SL or 10%TP hit