python进行日期的加减（秒-年）

1）timedelta函数的参数datetime.timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)2）日期计算的格式转换【代码块】import datetimedef result(v):print(type(v))print(v)print('\b')# a='202

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13705人浏览 · 2021-09-01 23:00:00

csdn__YX · 2021-09-01 23:00:00 发布

1）使用datetime模块进行日期的加减

timedelta函数：参数不包含“年”、“月”

【代码块】

"""
datetime.timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)
"""


import datetime

def result(v):
    print(type(v))
    print(v)
    print('\b')



# a='2021-09-01'  #给定一个开始日期
a=datetime.datetime.now()  
a=a.strftime("%Y-%m-%d")  #获取当前日期
result(a)

#将str格式的日期，解析为元祖格式，用于日期计算
b = datetime.datetime.strptime(a, "%Y-%m-%d")
result(b)


#日期做加减法
c=b-datetime.timedelta(days=10)
result(c)

#将datetime格式转换为str
d=c.strftime("%Y-%m-%d")
result(d)

【运行结果】

<class 'str'>
2021-09-01

<class 'datetime.datetime'>
2021-09-01 00:00:00

<class 'datetime.datetime'>
2021-08-22 00:00:00

<class 'str'>
2021-08-22

2）使用relativedelta函数，对日期进行加减

要使用relativedelta函数，需要先安装dateutil库。

【代码块】

"""
def __init__(self, dt1=None, dt2=None,
                 years=0, months=0, days=0, leapdays=0, weeks=0,
                 hours=0, minutes=0, seconds=0, microseconds=0,
                 year=None, month=None, day=None, weekday=None,
                 yearday=None, nlyearday=None,
                 hour=None, minute=None, second=None, microsecond=None)
"""

from dateutil.relativedelta import relativedelta
import datetime

def result(v):
    print(type(v))
    print(v)
    print('\b')

dt = '2021-9-2'
dt=datetime.datetime.strptime(dt,'%Y-%m-%d')
result(dt)


delta = dt + relativedelta(years=1)
result(datetime)

delta2 = delta.strftime('%Y-%m-%d')
result(delta2)

【运行结果】

<class 'datetime.datetime'>
2021-09-02 00:00:00

<class 'module'>
<module 'datetime' from '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/datetime.py'>

<class 'str'>
2022-09-02

3）demo

【代码块】


from dateutil.relativedelta import relativedelta
import datetime,time

today=datetime.datetime.now().strftime("%Y-%m-%d")  #[str]2021-09-03

now_timestamp=int(time.time())  #获取现在的时间戳
#获取今天0点的时间戳
today_datetime=time.strptime(today,"%Y-%m-%d")
today_timestamp=int(time.mktime(today_datetime))



#通过开时间时和周期，获取结束时间
"""
end_time=begin_time+relativedelta(months=cycle) #cycle=1，12
"""
def endday(begin_time,cycle):
    if isinstance(begin_time,str):
        begin_time=datetime.datetime.strptime(begin_time,"%Y-%m-%d")
        end_time=(begin_time+relativedelta(months=cycle,days=-1)).strftime("%Y-%m-%d")
        return end_time

    else:
        print("begin_time值需要传入str类型的参数")


begin_time="2021-03-01"
cycle=12
v=endday(begin_time,cycle)
print("合同开始日期%s，合同周期%s"%(begin_time,cycle))
print("合同结束日期%s"%v)

【运行结果】