分析用户下单行为

def solve():
    from pyodide.http import open_url
    from io import StringIO
    orders_csv = open_url(____).read()
    order_items_csv = open_url(____).read()
    users_csv = open_url(____).read()
    import pandas as pd
    from io import StringIO
    orders = pd.read_csv(StringIO(____))
    items = pd.read_csv(StringIO(____))
    users = pd.read_csv(StringIO(____))
    user_stats = orders.groupby(____).agg(
        order_count=(____),
        total_spend=(____),
        avg_order=(____),
    ).reset_index()
    user_stats = user_stats.merge(____)
    print(____)
    print(user_stats[['____','____','____','____']].sort_values(____).to_string(____))
    popular_skus = items.groupby(____)['____'].sum().sort_values(____)
    print(____)
    for sku, qty in popular_skus.head(____).items():
        print(____)
    completion_rate = len(____) / len(____)
    cancel_rate = len(____) / len(____)
    print(____)