dev-note
2018. 10. 4. 08:13
1. datetime 이용
1 2 3 | import datetime
int(datetime.datetime(2018, 10, 4).strftime("%j"))
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2. 직접 계산
1 2 3 4 5 6 7 8 9 10 11 12 | def juldate(year, month, day):
jmonth = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]
jday = jmonth[month - 1] + day
if (year % 4 == 0 and year % 100 != 0) or year % 400 == 0:
if month > 2:
return jday + 1
return jday
juldate(2018, 10, 4)
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2.1. 검증
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | import datetime
def juldate(year, month, day):
jmonth = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]
jday = jmonth[month - 1] + day
if (year % 4 == 0 and year % 100 != 0) or year % 400 == 0:
if month > 2:
return jday + 1
return jday
dt = datetime.date.fromtimestamp(0)
while dt.year <= 4000:
if int(datetime.datetime(dt.year, dt.month, dt.day).strftime("%j")) != juldate(dt.year, dt.month, dt.day):
print(dt)
break
dt += datetime.timedelta(days=1)
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성능 측정을 해봤다.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | import datetime
import timeit
def juldate(year, month, day):
jmonth = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]
jday = jmonth[month - 1] + day
if (year % 4 == 0 and year % 100 != 0) or year % 400 == 0:
if month > 2:
return jday + 1
return jday
start = timeit.default_timer()
dt = datetime.date.fromtimestamp(0)
while dt.year <= 4000:
juldate(dt.year, dt.month, dt.day)
dt += datetime.timedelta(days=1)
end = timeit.default_timer()
print(end - start)
start = timeit.default_timer()
dt = datetime.date.fromtimestamp(0)
while dt.year <= 4000:
int(datetime.datetime(dt.year, dt.month, dt.day).strftime("%j"))
dt += datetime.timedelta(days=1)
end = timeit.default_timer()
print(end - start)
1.6149210810011292
2.9324835093567865
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2배 정도 차이