实现设备数据分区键设计

def solve():
    from pyodide.http import open_url
    from io import StringIO
    import pandas as pd
    readings_csv = open_url(____).read()
    readings = pd.read_csv(StringIO(____))
    import datetime
    def get_partition_key(____):
        date_str = datetime.datetime.utcfromtimestamp(____).strftime(____)
        prefix = device_id[:____]
        return prefix + '____' + date_str
    readings = readings.copy()
    readings['____'] = readings.apply(lambda r: get_partition_key(____), axis=____)
    partition_sizes = readings.groupby(____).size()
    print(____)
    for pk, count in partition_sizes.items():
        print("____" + pk + "____" + str(____) + "____")
    print("____" + str(len(____)))
    print("____" + str(round(partition_sizes.mean(),____)))