Bekerja dengan datetime

Python Menengah untuk Keuangan

Kennedy Behrman

Data Engineer, Author, Founder

Atribut datetime

now.year
now.month
now.day

2019
11
13

now.hour
now.minute
now.second

22
34
56

Membandingkan datetime

sama dengan ==

kurang dari <

lebih dari >

Membandingkan datetime

from datetime import datetime
asian_crisis = datetime(1997, 7, 2)
world_mini_crash = datetime(1997, 10, 27)

asian_crisis > world_mini_crash

False

asian_crisis < world_mini_crash

True

Membandingkan datetime

asian_crisis = datetime(1997, 7, 2)
world_mini_crash = datetime(1997, 10, 27)

text = "10/27/1997"
format_str =  "%m/%d/%Y"
sell_date = datetime.strptime(text, format_str)

sell_date == world_mini_crash

True

Selisih antar datetime

Bandingkan dengan <, >, atau ==.
Pengurangan menghasilkan objek timedelta.
Atribut timedelta: weeks, days, minutes, seconds, microseconds

Selisih antar datetime

delta = world_mini_crash - asian_crisis

type(delta)

datetime.timedelta

delta.days

Membuat datetime relatif

dt

datetime.datetime(2019, 1, 14, 0, 0)

datetime(dt.year, dt.month, dt.day - 7)

datetime.datetime(2019, 1, 7, 0, 0)

datetime(dt.year, dt.month, dt.day - 15)

ValueError                                Traceback (most recent call last)
<ipython-input-28-804001f45cdb> in <module>()
-> 1 datetime(dt.year, dt.month, dt.day - 15)
ValueError: day is out of range for month

Membuat datetime relatif

delta = world_mini_crash - asian_crisis
type(delta)

datetime.timedelta

Membuat datetime relatif

from datetime import timedelta

offset = timedelta(weeks = 1)
offset

datetime.timedelta(7)

dt - offset

datetime.datetime(2019, 1, 7, 0, 0)

Membuat datetime relatif

offset = timedelta(days=16)
dt - offset

datetime.datetime(2018, 12, 29, 0, 0)

cur_week = last_week + timedelta(weeks=1)
# Do some work with date
# set last week variable to cur week and repeat
last_week = cur_week

source_dt = event_dt - timedelta(weeks=4)
# Use source datetime to look up market factors

Ayo berlatih!

Python Menengah untuk Keuangan