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262. 行程和用户

题目描述

表:Trips

+-------------+----------+
| Column Name | Type     |
+-------------+----------+
| id          | int      |
| client_id   | int      |
| driver_id   | int      |
| city_id     | int      |
| status      | enum     |
| request_at  | varchar  |     
+-------------+----------+
id 是这张表的主键(具有唯一值的列)。
这张表中存所有出租车的行程信息。每段行程有唯一 id ,其中 client_id 和 driver_id 是 Users 表中 users_id 的外键。
status 是一个表示行程状态的枚举类型,枚举成员为(‘completed’, ‘cancelled_by_driver’, ‘cancelled_by_client’) 。

 

表:Users

+-------------+----------+
| Column Name | Type     |
+-------------+----------+
| users_id    | int      |
| banned      | enum     |
| role        | enum     |
+-------------+----------+
users_id 是这张表的主键(具有唯一值的列)。
这张表中存所有用户,每个用户都有一个唯一的 users_id ,role 是一个表示用户身份的枚举类型,枚举成员为 (‘client’, ‘driver’, ‘partner’) 。
banned 是一个表示用户是否被禁止的枚举类型,枚举成员为 (‘Yes’, ‘No’) 。

 

取消率 的计算方式如下:(被司机或乘客取消的非禁止用户生成的订单数量) / (非禁止用户生成的订单总数)。

编写解决方案找出 "2013-10-01" 至 "2013-10-03" 期间非禁止用户(乘客和司机都必须未被禁止)的取消率。非禁止用户即 banned 为 No 的用户,禁止用户即 banned 为 Yes 的用户。其中取消率 Cancellation Rate 需要四舍五入保留 两位小数

返回结果表中的数据 无顺序要求

结果格式如下例所示。

 

示例 1:

输入: 
Trips 表:
+----+-----------+-----------+---------+---------------------+------------+
| id | client_id | driver_id | city_id | status              | request_at |
+----+-----------+-----------+---------+---------------------+------------+
| 1  | 1         | 10        | 1       | completed           | 2013-10-01 |
| 2  | 2         | 11        | 1       | cancelled_by_driver | 2013-10-01 |
| 3  | 3         | 12        | 6       | completed           | 2013-10-01 |
| 4  | 4         | 13        | 6       | cancelled_by_client | 2013-10-01 |
| 5  | 1         | 10        | 1       | completed           | 2013-10-02 |
| 6  | 2         | 11        | 6       | completed           | 2013-10-02 |
| 7  | 3         | 12        | 6       | completed           | 2013-10-02 |
| 8  | 2         | 12        | 12      | completed           | 2013-10-03 |
| 9  | 3         | 10        | 12      | completed           | 2013-10-03 |
| 10 | 4         | 13        | 12      | cancelled_by_driver | 2013-10-03 |
+----+-----------+-----------+---------+---------------------+------------+
Users 表:
+----------+--------+--------+
| users_id | banned | role   |
+----------+--------+--------+
| 1        | No     | client |
| 2        | Yes    | client |
| 3        | No     | client |
| 4        | No     | client |
| 10       | No     | driver |
| 11       | No     | driver |
| 12       | No     | driver |
| 13       | No     | driver |
+----------+--------+--------+
输出:
+------------+-------------------+
| Day        | Cancellation Rate |
+------------+-------------------+
| 2013-10-01 | 0.33              |
| 2013-10-02 | 0.00              |
| 2013-10-03 | 0.50              |
+------------+-------------------+
解释:
2013-10-01:
  - 共有 4 条请求,其中 2 条取消。
  - 然而,id=2 的请求是由禁止用户(user_id=2)发出的,所以计算时应当忽略它。
  - 因此,总共有 3 条非禁止请求参与计算,其中 1 条取消。
  - 取消率为 (1 / 3) = 0.33
2013-10-02:
  - 共有 3 条请求,其中 0 条取消。
  - 然而,id=6 的请求是由禁止用户发出的,所以计算时应当忽略它。
  - 因此,总共有 2 条非禁止请求参与计算,其中 0 条取消。
  - 取消率为 (0 / 2) = 0.00
2013-10-03:
  - 共有 3 条请求,其中 1 条取消。
  - 然而,id=8 的请求是由禁止用户发出的,所以计算时应当忽略它。
  - 因此,总共有 2 条非禁止请求参与计算,其中 1 条取消。
  - 取消率为 (1 / 2) = 0.50

解法

方法一

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import pandas as pd


def trips_and_users(trips: pd.DataFrame, users: pd.DataFrame) -> pd.DataFrame:
    # 1) temporal filtering
    trips = trips[trips["request_at"].between("2013-10-01", "2013-10-03")].rename(
        columns={"request_at": "Day"}
    )

    # 2) filtering based not banned
    # 2.1) mappning the column 'banned' to `client_id` and `driver_id`
    df_client = (
        pd.merge(trips, users, left_on="client_id", right_on="users_id", how="left")
        .drop(["users_id", "role"], axis=1)
        .rename(columns={"banned": "banned_client"})
    )
    df_driver = (
        pd.merge(trips, users, left_on="driver_id", right_on="users_id", how="left")
        .drop(["users_id", "role"], axis=1)
        .rename(columns={"banned": "banned_driver"})
    )
    df = pd.merge(
        df_client,
        df_driver,
        left_on=["id", "driver_id", "client_id", "city_id", "status", "Day"],
        right_on=["id", "driver_id", "client_id", "city_id", "status", "Day"],
        how="left",
    )
    # 2.2) filtering based on not banned
    df = df[(df["banned_client"] == "No") & (df["banned_driver"] == "No")]

    # 3) counting the cancelled and total trips per day
    df["status_cancelled"] = df["status"].str.contains("cancelled")
    df = df[["Day", "status_cancelled"]]
    df = df.groupby("Day").agg(
        {"status_cancelled": [("total_cancelled", "sum"), ("total", "count")]}
    )
    df.columns = df.columns.droplevel()
    df = df.reset_index()

    # 4) calculating the ratio
    df["Cancellation Rate"] = (df["total_cancelled"] / df["total"]).round(2)
    return df[["Day", "Cancellation Rate"]]
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# Write your MySQL query statement below
SELECT
    request_at AS Day,
    ROUND(AVG(status != 'completed'), 2) AS 'Cancellation Rate'
FROM
    Trips AS t
    JOIN Users AS u1 ON (t.client_id = u1.users_id AND u1.banned = 'No')
    JOIN Users AS u2 ON (t.driver_id = u2.users_id AND u2.banned = 'No')
WHERE request_at BETWEEN '2013-10-01' AND '2013-10-03'
GROUP BY request_at;

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