如果行符合条件,我正在尝试创建重复行.在下表中,我创建了一个基于groupby的累积计数,然后是groupby的MAX的另一个计算.
df['PathID'] = df.groupby(DateCompleted).cumcount() + 1
df['MaxPathID'] = df.groupby(DateCompleted)['PathID'].transform(max)
Date Completed PathID MaxPathID
1/31/17 1 3
1/31/17 2 3
1/31/17 3 3
2/1/17 1 1
2/2/17 1 2
2/2/17 2 2
在这种情况下,我想只复制2/1/17的记录,因为该日期只有一个实例(即MaxPathID == 1).
期望的输出：
Date Completed PathID MaxPathID
1/31/17 1 3
1/31/17 2 3
1/31/17 3 3
2/1/17 1 1
2/1/17 1 1
2/2/17 1 2
2/2/17 2 2
提前致谢！
解决方法:
我认为您需要按完成日期获取唯一行,然后将concat行添加到原始行：
df1 = df.loc[~df['Date Completed'].duplicated(keep=False), ['Date Completed']]
print (df1)
Date Completed
3 2/1/17
df = pd.concat([df,df1], ignore_index=True).sort_values('Date Completed')
df['PathID'] = df.groupby('Date Completed').cumcount() + 1
df['MaxPathID'] = df.groupby('Date Completed')['PathID'].transform(max)
print (df)
Date Completed PathID MaxPathID
0 1/31/17 1 3
1 1/31/17 2 3
2 1/31/17 3 3
3 2/1/17 1 2
6 2/1/17 2 2
4 2/2/17 1 2
5 2/2/17 2 2
编辑：
print (df)
Date Completed a b
0 1/31/17 4 5
1 1/31/17 3 5
2 1/31/17 6 3
3 2/1/17 7 9
4 2/2/17 2 0
5 2/2/17 6 7
df1 = df[~df['Date Completed'].duplicated(keep=False)]
#alternative - boolean indexing by numpy array
#df1 = df[~df['Date Completed'].duplicated(keep=False).values]
print (df1)
Date Completed a b
3 2/1/17 7 9
df = pd.concat([df,df1], ignore_index=True).sort_values('Date Completed')
print (df)
Date Completed a b
0 1/31/17 4 5
1 1/31/17 3 5
2 1/31/17 6 3
3 2/1/17 7 9
6 2/1/17 7 9
4 2/2/17 2 0
5 2/2/17 6 7