我有一個 Pandas df，它有 2 列Day (Date in datetime format) 和Number of Troubleshootings。我想創建兩個新列，第一個是上一個故障事件的天數（我已經完成了），第二個是下一個故障事件的天數（我很難做到）。Day Number of breakdowns Days from Previous Breakdown Event2017-01-09 0.0 0 2017-01-12 0.0 02017-01-13 0.0 02017-01-14 0.0 02017-01-16 1.0 02017-01-17 0.0 12017-01-18 0.0 22017-01-19 1.0 02017-01-20 0.0 12017-01-21 0.0 22017-01-23 1.0 0上次故障事件的天數計算自故障發生以來經過的天數。代碼：s = df.groupby(df['Number of breakdowns'].ne(0).cumsum())['Day'].transform('first')df['Days from Previous Breakdown Event'] = (df['Day'] - s).dt.dayszeros_index = df['Number of breakdowns'].ne(0).idxmax()df.loc[:zeros_index,'Days from Previous Breakdown Event'] = 0
1 回答
慕少森
TA貢獻2019條經驗 獲得超9個贊
iloc[::-1]用transform和交換順序last，然后也交換s - df['Day']：
s = df.groupby(df['Number of breakdowns'].iloc[::-1].ne(0).cumsum())['Day'].transform('last')
df['Days from Next Breakdown Event'] = (s - df['Day']).dt.days
print (df)
Day Number of breakdowns Days from Previous Breakdown Event \
0 2017-01-09 0.0 0
1 2017-01-12 0.0 0
2 2017-01-13 0.0 0
3 2017-01-14 0.0 0
4 2017-01-16 1.0 0
5 2017-01-17 0.0 1
6 2017-01-18 0.0 2
7 2017-01-19 1.0 0
8 2017-01-20 0.0 1
9 2017-01-21 0.0 2
10 2017-01-23 1.0 0
Days from Next Breakdown Event
0 7
1 4
2 3
3 2
4 0
5 2
6 1
7 0
8 3
9 2
10 0
詳情：
print (s)
0 2017-01-16
1 2017-01-16
2 2017-01-16
3 2017-01-16
4 2017-01-16
5 2017-01-19
6 2017-01-19
7 2017-01-19
8 2017-01-23
9 2017-01-23
10 2017-01-23
Name: Day, dtype: datetime64[ns]
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