given stock price change with time, find best buy and sell point

maxProfit.py

def find_max_profit(args):
    
    _min = None
    diff = 0
    buyPoint = 0
    sellPoint = 0
    
    for i in range(len(args)):
        
        if not _min:
            _min = args[i]
            
        if args[i] <= _min:
            _min = args[i]
            buyPoint = i
            
        if (args[i] - _min) > diff:
            sellPoint = i
            diff = args[i] - _min
    
    return buyPoint, sellPoint, diff

def test_find_max_profit():
    args = [5, 5, 5, 2, 3, 1, 5, 5, 7, 1, 9]
    assert find_max_profit(args) == (9, 10, 8)
    
test_find_max_profit()