实现渠道降级处理主渠道故障备用渠道

def solve():
    from pyodide.http import open_url
    account_types_csv = open_url(____).read()
    payment_channels_csv = open_url(____).read()
    transfer_types_csv = open_url(____).read()
    transaction_limits_csv = open_url(____).read()
    accounts_csv = open_url(____).read()
    transfers_csv = open_url(____).read()
    channel_stats_csv = open_url(____).read()
    import sqlite3, pandas as pd
    from io import StringIO
    conn = sqlite3.connect(____)
    pd.read_csv(StringIO(____)).to_sql(____)
    primary = pd.read_sql_query(____).iloc[____]
    print(____)
    if primary['____'] != '____':
        backup = pd.read_sql_query(____).iloc[____]
        print(____)
    else:
        print(____)
    conn.close()