实现缓存雪崩防御（随机TTL）

def solve():
    from pyodide.http import open_url
    from io import StringIO
    products_csv = open_url(____).read()
    import pandas as pd, random
    random.seed(____)
    from io import StringIO
    products = pd.read_csv(StringIO(____))
    def fixed_ttl(____): return base
    def random_ttl(____): return base + random.randint(____)
    def stagger_ttl(____): return base + idx * step
    NOW = ____
    print(____)
    fixed_exps = [NOW + fixed_ttl() for _ in products['____']]
    from collections import Counter
    print(____)
    print(____)
    rand_exps = [NOW + random_ttl() for _ in products['____']]
    exp_range = max(____) - min(____)
    print(____)
    print(____)
    stagger_exps = [NOW + stagger_ttl(____) for i in range(len(____))]
    print(____)
    print(____)