我有一个 pandas 数据框 df_sample:
columna columnb
a aa
a ab
b ba
b bb
b bc
我已经创建了一个随机列,其中包含一些日期对象:
df_sample['contract_starts'] = np.random.choice(pd.date_range('2024-01-01', '2024-05-01'), len(df_sample))
这会导致以下输出:
columna columnb contract_starts
a aa 2024-01-21
a ab 2024-03-03
b ba 2024-01-18
b bb 2024-02-18
b bc 2024-04-03
如何创建另一个日期时间列contract_noted,该值也有给定范围(例如直到 2024-05-01 )但不超过 contract_starts
column,例如:
columnA columnB contract_starts contract_noted
A AA 2024-01-21 2024-01-20
A AB 2024-03-03 2024-01-01
B BA 2024-01-18 2024-01-13
B BB 2024-02-18 2024-02-01
B BC 2024-04-03 2024-03-28
正确答案
您可以通过 从 contract_starts
列中减去随机时间增量numpy.random.randint
与 to_timedelta
< /a>:
df_sample['contract_noted'] = (df_sample['contract_starts'] -
pd.to_timedelta(np.random.randint(1,30, len(df_sample)),
unit='d'))
print (df_sample)
columna columnb contract_starts contract_noted
0 a aa 2024-04-18 2024-03-21
1 a ab 2024-02-12 2024-01-22
2 b ba 2024-02-21 2024-02-02
3 b bb 2024-04-12 2024-03-29
4 b bc 2024-02-10 2024-02-03
如果还需要开始和结束之间的日期时间,如 contract_starts
生成 1
之间的 inetegers 以及与开始日期时间的差异:
days =(df_sample['contract_starts'] - pd.Timestamp('2024-01-01')).dt.days
print (days)
df_sample['contract_noted'] = (df_sample['contract_starts'] -
pd.to_timedelta(np.random.randint(1,days, len(df_sample)),
unit='d'))
print (df_sample)
columnA columnB contract_starts contract_noted
0 A AA 2024-02-09 2024-01-09
1 A AB 2024-04-26 2024-02-23
2 B BA 2024-04-10 2024-04-06
3 B BB 2024-01-31 2024-01-07
4 B BC 2024-01-14 2024-01-08