Online Stock Span Python Solution with Tests

lcpy gen -n 901   # by problem number
lcpy gen -s online_stock_span   # by problem name

Input
["StockSpanner", "next", "next", "next", "next", "next", "next", "next"]
[[], [100], [80], [60], [70], [60], [75], [85]]
Output
[null, 1, 1, 1, 2, 1, 4, 6]

Explanation
StockSpanner stockSpanner = new StockSpanner();
stockSpanner.next(100); // return 1
stockSpanner.next(80);  // return 1
stockSpanner.next(60);  // return 1
stockSpanner.next(70);  // return 2
stockSpanner.next(60);  // return 1
stockSpanner.next(75);  // return 4, because the last 4 prices (including today's price of 75) were less than or equal to today's price.
stockSpanner.next(85);  // return 6

class StockSpanner:
    # Time: O(1) amortized per next call
    # Space: O(n)
    def __init__(self) -> None:
        # Monotonic decreasing stack of (price, span) pairs.
        self.stack: list[tuple[int, int]] = []

    def next(self, price: int) -> int:
        span = 1
        while self.stack and self.stack[-1][0] <= price:
            span += self.stack.pop()[1]
        self.stack.append((price, span))
        return span