两个日期之间的差异产生不同的结果

Question

Below is the example of a sample pandas dataframe and I am trying to find the difference between the dates in the two rows (with least dated row as the base - in this case second row). The difference between 2 dates is > than 90 days, hence I am expecting "false" for 2 rows. But for some reason, the result looks different.

PH_number   date        Type
H09879721   2018-10-29  AccountHolder
H09879731   2018-07-24  AccountHolder

Code:
print(df.date.diff()<=pd.Timedelta(90,'d'))

Current Result:
False
True

Expected Result:
False
False

Any suggestions would be appreciated.

Answer 1

Use abs this takes care when difference is negative:

df.date.diff().abs().dt.days<=90

Or:

df.date.diff().abs().dt.days.le(90)

Or:

df.date.diff().abs()<=pd.Timedelta(90,'d')

Or:

df.date.diff().abs().le(pd.Timedelta(90,'d'))

---

0    False
1    False
Name: date, dtype: bool