使用列作為邊界創建行譜 pandas 數據幀

Question

我有以下pandas DF：

import pandas as pd

mission_df = pd.DataFrame(
    {'mission': [1, 2, 3],
     'type': ['lift', 'talk', 'run'],
     'boundary_low': [2, 3, 3],
     'boundary_high': [3, 8, 12]})

我想向每個字段（示例任務）添加行，以便每一行將根據離散跳躍的邊界填充，例如任務 1 的邊界在 2 和 3 之間，所以我需要該任務添加 2 行值 2 和 3，如下所示：

desired_df = pd.DataFrame(
    {'mission': [1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3],
     'amount': [2, 3, 3, 4, 5, 6, 7, 8, 3, 4, 5, 6],
     'type': ['lift', 'lift', 'talk', 'talk', 'talk', 'talk', 'talk', 'talk', 'run', 'run', 'run', 'run'],
     'boundary_low': [2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3],
     'boundary_high': [3, 3, 8, 8, 8, 8, 8, 8, 6, 6, 6, 6]})

提前致謝！

Answer 1

嘗試：

mission_df = mission_df.loc[mission_df.index.repeat(mission_df["boundary_high"]-mission_df["boundary_low"] + 1)]

mission_df['amount'] = mission_df.assign(amount=1).groupby(['mission', 'type'])['amount'].cumsum() + mission_df['boundary_low'].sub(1)

# not sure, if relevant for you:
mission_df.reset_index(drop=True, inplace=True)

這里的關鍵 function （為了簡單起見）是：

pd.Index.repeat(n) ，來源： https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Index.repeat.html

輸出：

    mission  type  boundary_low  boundary_high  amount
0         1  lift             2              3       2
1         1  lift             2              3       3
2         2  talk             3              8       3
3         2  talk             3              8       4
4         2  talk             3              8       5
5         2  talk             3              8       6
6         2  talk             3              8       7
7         2  talk             3              8       8
8         3   run             3             12       3
9         3   run             3             12       4
10        3   run             3             12       5
11        3   run             3             12       6
12        3   run             3             12       7
13        3   run             3             12       8
14        3   run             3             12       9
15        3   run             3             12      10
16        3   run             3             12      11
17        3   run             3             12      12