の説明からの抜粋dateutil.relativedelta.relativedelta、
年、月、日、時、分、秒、マイクロ秒:
Absolute information (argument is singular); adding or subtracting a relativedelta with absolute information does not perform an aritmetic operation, but rather REPLACES the corresponding value in the original datetime with the value(s) in relativedelta.年、月、週、日、時、分、秒、マイクロ秒:
Relative information, may be negative (argument is plural); adding or subtracting a relativedelta with relative information performs the corresponding aritmetic operation on the original datetime value with the information in the relativedelta.
足し算と引き算に関しては、次の例との違いがわかります。
>>> from datetime import datetime
>>> from dateutil.relativedelta import relativedelta
>>> now = datetime.now()
>>> str(now)
'2016-05-23 22:32:48.427269'
>>> singular = relativedelta(month=3)
>>> plural = relativedelta(months=3)
# subtracting
>>> str(now - singular) # replace the corresponding value in the original datetime with the value(s) in relativedelta
'2016-03-23 22:32:48.427269'
>>> str(now - plural) # perform the corresponding aritmetic operation on the original datetime value with the information in the relativedelta.
'2016-02-23 22:32:48.427269'
# adding
>>> str(now + singular) # replace the corresponding value in the original datetime with the value(s) in relativedelta
'2016-03-23 22:32:48.427269'
>>> str(now + plural) # perform the corresponding aritmetic operation on the original datetime value with the information in the relativedelta.
'2016-08-23 22:32:48.427269'
これ以外に、 の単数引数と複数引数の違いは何relativedeltaですか?