Datetime

時間格式代碼

• %d：以十進製表示的月份中的第幾天，填充零。
• %m：十進製表示的月份，零填充。
• %y：以零填充的十進製表示法的年份的最後兩位數字。
• %Y：以十進製表示的四位年份數字，零填充。
• %H：當以十進製表示並填充零時（24 小時制）
• %I：當以十進製表示並填充零時（12 小時制）
• %M：用於填充零的十進製表示法。
• %S：以十進製表示的秒數，填充零。
• %f：十進製表示法中的微秒（6 位），填充 0。
• %A：區域設置的星期幾的名稱
• %a：區域設置的日期名稱（縮寫形式）
• %B：語言環境月份名稱
• %b：語言環境月份名稱（縮寫形式）
• %j：以十進制記數法表示的年份中的第幾天，零填充。
• %U：以十進製表示的年份中的周數，零填充（該週從星期日開始）
• %W：以十進製表示的年份週數，零填充（每週從星期一開始）

Today, Now

import datetime

dt_now = datetime.datetime.now()
print(dt_now)
# 2018-02-02 18:31:13.271231

print(type(dt_now))
# <class 'datetime.datetime'>

print(dt_now.year)
# 2018

print(dt_now.hour)
# 18

String to Datetime

• strptime() : 從字符串到日期和時間的轉換

from datetime import datetime

date_str = '09-19-2022'

date_object = datetime.strptime(date_str, '%m-%d-%Y').date()
print(type(date_object))
print(date_object)  # printed in default format

# Output:
# <class 'datetime.date'>
# 2022-09-19

from datetime import datetime

time_str = '13::55::26'
time_object = datetime.strptime(time_str, '%H::%M::%S').time()
print(type(time_object))
print(time_object)

# Output:
# <class 'datetime.time'>
# 13:55:26

from datetime import datetime
import locale

locale.setlocale(locale.LC_ALL, 'de_DE')
date_str_de_DE = '16-Dezember-2022 Freitag'  # de_DE locale
datetime_object = datetime.strptime(date_str_de_DE, '%d-%B-%Y %A')
print(type(datetime_object))
print(datetime_object)

# Output:
# <class 'datetime.datetime'>
# 2022-12-16 00:00:00

date

• strftime() : 從日期和時間到字符串的轉換

import datetime
d = datetime.date(2020,1,1)   # 2020-01-01

import datetime
today = datetime.date.today()
print(today)                 # 2021-10-19
print(today.year)            # 2021
print(today.month)           # 10
print(today.day)             # 19
print(today.weekday())       # 1    ( 因為是星期二，所以是 1 )
print(today.isoweekday())    # 2    ( 因為是星期二，所以是 2 )
print(today.isocalendar())   # (2021, 42, 2)  ( 第三個數字是星期二，所以是 2 )
print(today.isoformat())     # 2021-10-19
print(today.ctime())         # Tue Oct 19 00:00:00 2021
print(today.strftime('%Y.%m.%d'))    # 2021.10.19

newDay = today.replace(year=2020)
print(newDay)                # 2020-10-19

import datetime
d1 = datetime.date(2020, 6, 24)
d2 = datetime.date(2021, 11, 24)
print(abs(d1-d2).days)       # 518

time

import datetime
thisTime = datetime.time(12,0,0,1)
print(thisTime)   # 12:00:00.000001

import datetime
thisTime = datetime.time(14,0,0,1,tzinfo=datetime.timezone(datetime.timedelta(hours=8)))
print(thisTime)               # 14:00:00.000001+08:00
print(thisTime.isoformat())   # 14:00:00.000001+08:00
print(thisTime.tzname())      # UTC+08:00
print( thisTime.strftime('%H:%M:%S'))   # 14:00:00

newTime = today.replace(hour=20)
print(newTime)                # 20:00:00.000001+08:00

datetime

• datetime.datetime：日期和時間（日期和時間）
• datetime.date：日期
• datetime.time：時間
• datetime.timedelta：時差和經過時間

import datetime
thisTime = datetime.datetime(2020,1,1,20,20,20,20)
print(thisTime)    # 2020-01-01 20:20:20.000020

import datetime
print(datetime.datetime.today())    # 2021-10-19 06:15:46.022925
print(datetime.datetime.now(tz=datetime.timezone(datetime.timedelta(hours=8))))
# 2021-10-19 14:15:46.027982+08:00
print(datetime.datetime.utcnow())   # 2021-10-19 06:15:46.028630

import datetime
now = datetime.datetime.now(tz=datetime.timezone(datetime.timedelta(hours=8)))
print(now)                # 2021-10-19 14:25:46.962975+08:00
print(now.date())         # 2021-10-19
print(now.time())         # 14:25:46.962975
print(now.tzname())       # UTC+08:00
print(now.weekday())      # 1
print(now.isoweekday())   # 2
print(now.isocalendar())  # (2021, 42, 2)
print(now.isoformat())    # 2021-10-19 14:25:46.962975+08:00
print(now.ctime())        # Tue Oct 19 14:48:38 2021
print(now.strftime('%Y/%m/%d %H:%M:%S'))  # 2021/10/19 14:48:38
print(now.timetuple())    # time.struct_time(tm_year=2021, tm_mon=10, tm_mday=19, tm_hour=16, tm_min=8, tm_sec=6, tm_wday=1, tm_yday=292, tm_isdst=-1)

timedelta

日期/時間計算

import datetime
today = datetime.datetime.now()
yesterday = today - datetime.timedelta(days=1)
tomorrow = today + datetime.timedelta(days=1)
nextweek = today + datetime.timedelta(weeks=1)
print(today)       # 2021-10-19 07:01:22.669886
print(yesterday)   # 2021-10-18 07:01:22.669886
print(tomorrow)    # 2021-10-20 07:01:22.669886
print(nextweek)    # 2021-10-26 07:01:22.669886

Timezone

import datetime
tzone = datetime.timezone(datetime.timedelta(hours=8))
now = datetime.datetime.now(tz=tzone)
print(now)    # 2021-10-19 15:07:51.128092+08:00

from datetime import datetime, timezone

# Get the current time in UTC
utc_time = datetime.now(timezone.utc)

print(utc_time)

from datetime import datetime
import pytz

timezone = pytz.timezone("America/New_York")

current_time_in_timezone = datetime.now(timezone)

print(current_time_in_timezone)

Sleep

import time

time.sleep(5) # Pauses the code for 5 seconds

Timestamp

Get Current Time in Milliseconds

milliseconds_since_epoch = time.time() * 1000

Get Current Timestamp

current_timestamp = time.time()

print(current_timestamp)

Timestamp to a human-readable date

timestamp = time.time()

readable_date = datetime.fromtimestamp(timestamp)

print(readable_date)

Time Diff.

time1 = datetime.now()

# ... some operations ...

time2 = datetime.now()

difference = time2 - time1

print(difference)

start_time = time.time()

# ... some operations ...

end_time = time.time()

elapsed_time = end_time - start_time

print(f"Time elapsed: {elapsed_time} seconds")

函式：日期轉換週

import datetime

def dow(date):
    dateobj = datetime.datetime.strptime(date, r"%Y-%m-%d")
    return dateobj.strftime("%A")

date_str = "2024-12-11"
print(dow(date_str))  # Output: Wednesday

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  datetime (strftime, strptime) 中將日期和時間與字符串相互轉換 | From-Locals