python – 如何检查循环范围的重叠(重叠的年度循环周期)

例如,期间A =(3月1日至5月1日)和期间B =(4月1日至9月1日)重叠.
此外,期间A =(10月1日至2月1日)和期间B =(1月1日至3月1日)重叠.

但是,我发现这比我预想的要困难得多.复杂性来自于跨越年底的时期.

我有一个有效的解决方案(参见下面的doOverlap(A,B)方法),但我发现它令人沮丧.

# for the rest of the MWE context code,see further
# WORKING,but a bit convulted
def doesOverlap(A,B):  
    '''returns True if yearly period A and B have overlapping dates'''
    # list to track if day in year is part of a period A
    # (this could probably be done a bit cheaper with a dictionary of tuples,but not relevant for my question)
    yeardayCovered = [False for x in range(366)]  # leap year

    # mark the days of A
    for d in range(A.start,A.start + A.length):
        yeardayCovered[d % 366] = True

    # now check each of the days in B with A
    for d in range(B.start,B.start + B.length):
        if yeardayCovered[d % 366]:
            return True
    return False

我相信应该可以用更少的支票和更优雅的方式来做到这一点.我已经尝试将其中一个开始日设置为零偏移,应用一些模运算符,然后是常规(非循环)范围重叠检查(Algorithm to detect overlapping periods).但我还没有为我的所有测试用例工作.

#NOT WORKING CORRECTLY!!
def doesOverlap(A,B):   
    '''determines if two yearly periods have overlapping dates'''
    Astart = A.start
    Astop = A.stop
    Bstart = B.start
    Bstop = B.stop

    # start day counting at Astart,at 0
    offset = Astart
    Astart = 0
    Astop = (Astop - offset) % 366
    Bstart = (Bstart - offset) % 366
    Bstop = (Bstop - offset) % 366

    # overlap?
    # https://stackoverflow.com/a/13513973
    return (Astart <= Bstop and Bstart <= Astop)

注意：我已经用Python完成了代码,但理想情况下解决方案应该不是特定于Python的(即不使用通常只在Python中可用的函数,而不是在C或C#中)

# MWE (Minimal Working Example)

import datetime
import unittest


class TimePeriod:
    def __init__(self,startDay,startMonth,stopDay,stopMonth):
        self.startDay = startDay
        self.startMonth = startMonth
        self.stopDay = stopDay
        self.stopMonth = stopMonth

    def __repr__(self):
        return "From " + str(self.startDay) + "/" + str(self.startMonth) + " to " + 
            str(self.stopDay) + "/" + str(self.stopMonth)

    def _dayOfYear(self,d,m,y=2012):
        '''2012 = leap year'''
        date1 = datetime.date(year=y,day=d,month=m)
        return date1.timetuple().tm_yday

    @property
    def start(self):
        '''day of year of start of period,zero-based for easier modulo operations! '''
        return self._dayOfYear(self.startDay,self.startMonth) - 1

    @property
    def stop(self):
        '''day of year of stop of period,zero-based for easier modulo operations! '''
        return self._dayOfYear(self.stopDay,self.stopMonth) - 1

    @property
    def length(self):
        '''number of days in the time period'''
        _length = (self.stop - self.start) % 366 + 1
        return _length

def doesOverlap(A,B):
    # code from above goes here


class TestPeriods(unittest.TestCase):
    pass


def test_generator(a,b,c):
    def test(self):
        self.assertEqual(doesOverlap(a,b),c)
    return test

if __name__ == '__main__':

    #some unit tests,probably not complete coverage of all edge cases though
    tests = [["max",TimePeriod(1,1,31,12),1),True],["BinA",3,11),5,10),["BoverEndA",2),TimePeriod(10,3),["BafterA",TimePeriod(2,2,False],["sBoutA",12,5),6,7),["sBoverBeginA",11,10,["sBinA",["sBinA2",["sBinA3",["Leap",TimePeriod(29,4),["BtouchEndA",True]]

    for i,t in enumerate(tests):
        test_name = 'test_%s' % t[0]
        test = test_generator(t[1],t[2],t[3])
        setattr(TestPeriods,test_name,test)

    # unittest.main()
    suite = unittest.TestLoader().loadTestsFromTestCase(TestPeriods)
    unittest.TextTestRunner(verbosity=2).run(suite)