Token amount calculation to set slippage for Pancakeswap tx

Question

I have a simple code to calculates the needed token amount for the cases when I buy a token with 5% slippage. I just simply check how many tokens could I receive for the current price, get its 95% and use the amount for the swapExactETHForTokens function's amountOutMin. My question is that should I pay attention for the decimal of the token? Is there any scenario when I have to use it to calculate the correct token number which fits to the slippage?

This is how I do it now. I don't use the decimal at all.

def get_slippage(token_price, budget, slippage_percentage):
    original_amount = round(budget / token_price)
    one_percent = original_amount / 100
    token_amount_slippage_5p = round(one_percent * slippage_percentage)
    return token_amount_slippage_5p

Answer 1

You do need to worry about the decimals. You cannot use absolute values because it will mean a completely different number, 100 for a token with 18 decimals would mean 10 ** 16, if there are sandwiches out there, they will sandwich all of it and you will get exactly that, minOut is an important parameter to protect yourself against big slippage and sandwiches.