创建新的DF Col值，其中X和Y之间的时间范围

Question

Sample data我想创建一个新列，其值依赖于包含日期时间或时间数据的另一列。所以当时间介于[x]和[y]之间时，新列的值是Z，其中Z是一个整数。

我知道当价格超过100时，df['newColumn'] = np.where(df['price']>=100, 'yes', 'no')会创建一个带有yes和nos的新列。我想用我的Panda数据框做类似的事情，指定X和Y之间的时间范围，将新的列添加“1”，elif X2和Y2之间的时间范围，向列添加“2”，依此类推。

我确实看到df.loc['2002-1-1 01:00:00':'2002-1-1 04:00:00']作为选择时间范围的一种手段，但不能把两者放在一起。任何人的想法？

Answer 1

我相信你需要between与np.where或铸造布尔到ints然后到strings：

rng = pd.date_range('2010-03-12 15:00:00', periods=10, freq='20H')
X = pd.DataFrame({'Datetime': rng})  

mask = X['Datetime'].between('2010-03-12 16:49:00', '2010-03-14 16:49:00')
#solution1
X['CLASS'] = np.where(mask,'1','0')
#solution2
#X['CLASS'] = mask.astype(int).astype(str)

print (X)

             Datetime CLASS
0 2010-03-12 15:00:00     0
1 2010-03-13 11:00:00     1
2 2010-03-14 07:00:00     1
3 2010-03-15 03:00:00     0
4 2010-03-15 23:00:00     0
5 2010-03-16 19:00:00     0
6 2010-03-17 15:00:00     0
7 2010-03-18 11:00:00     0
8 2010-03-19 07:00:00     0
9 2010-03-20 03:00:00     0

编辑：

rng = pd.date_range('2010-03-12 16:35:00', periods=30, freq='T')
X = pd.DataFrame({'Datetime': rng})  

#same output as below
#conditions = [X['Datetime'] < '2010-03-12 16:39:00', 
#              (X['Datetime'] < '2010-03-12 16:49:00') & (X['Datetime']>= '2010-03-12 16:39:00'),
#              X['Datetime']>='2010-03-12 17:01:00'] 

conditions = [X['Datetime'] < '2010-03-12 16:39:00', 
              X['Datetime'].between('2010-03-12 16:39:00','2010-03-12 16:48:00'),
              X['Datetime']>='2010-03-12 17:01:00'] 

classes = ['0','1','2'] 
#gaps are repalced to NaNs
X['CLASS'] = np.select(conditions, classes, default=np.nan)

#if want bin all data without gaps
bins = pd.DatetimeIndex(['1900-01-01', '2010-03-12 16:38:00', '2010-03-12 16:48:00', '2262-04-11'])
labels=['0','1','2'] 
X['label'] = pd.cut(X['Datetime'], bins=bins, labels=labels, right=True)

---

print (X)

              Datetime CLASS label
0  2010-03-12 16:35:00     0     0
1  2010-03-12 16:36:00     0     0
2  2010-03-12 16:37:00     0     0
3  2010-03-12 16:38:00     0     0
4  2010-03-12 16:39:00     1     1
5  2010-03-12 16:40:00     1     1
6  2010-03-12 16:41:00     1     1
7  2010-03-12 16:42:00     1     1
8  2010-03-12 16:43:00     1     1
9  2010-03-12 16:44:00     1     1
10 2010-03-12 16:45:00     1     1
11 2010-03-12 16:46:00     1     1
12 2010-03-12 16:47:00     1     1
13 2010-03-12 16:48:00     1     1
14 2010-03-12 16:49:00   nan     2
15 2010-03-12 16:50:00   nan     2
16 2010-03-12 16:51:00   nan     2
17 2010-03-12 16:52:00   nan     2
18 2010-03-12 16:53:00   nan     2
19 2010-03-12 16:54:00   nan     2
20 2010-03-12 16:55:00   nan     2
21 2010-03-12 16:56:00   nan     2
22 2010-03-12 16:57:00   nan     2
23 2010-03-12 16:58:00   nan     2
24 2010-03-12 16:59:00   nan     2
25 2010-03-12 17:00:00   nan     2
26 2010-03-12 17:01:00     2     2
27 2010-03-12 17:02:00     2     2
28 2010-03-12 17:03:00     2     2
29 2010-03-12 17:04:00     2     2