Python - Calculate date difference in months - python-3.x

I need to get the difference between the days in months and days (eg. 3months 20days).
from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime('2019-06-23', "%Y-%m-%d")
date2 = datetime.strptime('2018-04-17', '%Y-%m-%d')
r = relativedelta.relativedelta(date1, date2)
print(r)
This gives me result like relativedelta(years=+1, months=+2, days=+6) whereas I need result like 14 months 6 days
Thank you

Incorporate a minor modification to get the answer.
print(r.years, 'years,', r.months,'months and', r.days, 'days')

Related

Get dynamic dates for URL on any day of the month

I'm scraping a website with requests. The URL requires dynamic dates so i'm generating the dates to use with the following variables:
stmDt = (pd.to_datetime('today').date()+ pd.offsets.MonthBegin(-1)).strftime('%d-%b-%Y')
todDt = (pd.to_datetime('today').date()).strftime('%d-%b-%Y')
snmDt = (pd.to_datetime('today').date()+ pd.offsets.MonthBegin(1)).strftime('%d-%b-%Y')
enmDt = (pd.to_datetime('today').date()+ pd.offsets.MonthEnd(2)).strftime('%d-%b-%Y')
For this example, i'm running this script on 11/30/2022 (last day of the month).
stmDt = start this month date (first day of month on which we run script - 11/1/2022)
todDt = today (11/30/2022)
snmDt = start next month (12/1/2022)
enmDt = end next month (12/31/2022)
The date variables are correct most of the time, but it appears (for november run dates):
On the first day of the month: stmDt shows the first day of the
previous month (10/1/22)
On the last day of the month: enmDt shows the last day two months
from now (1/31/23)
How can I tweak these so they always give me the correct dates? Happy to use other packages to accomplish etc
Thanks
You can do this using dateutil.relativedelta like this:
from datetime import datetime
from dateutil.relativedelta import relativedelta
today = datetime.now()
stmDt = today.replace(day=1).strftime('%d-%b-%Y')
todDt = today.strftime('%d-%b-%Y')
snmDt = (today + relativedelta(months=1)).replace(day=1).strftime('%d-%b-%Y')
enmDt = ((today + relativedelta(months=2)).replace(day=1) - relativedelta(days=1)).strftime('%d-%b-%Y')

Get last day of week of a given date

Given any day of the year, such as today, I would have the last day of the current week.
For example, current day is 2021-12-27 (Monday), so the last day of this week is 2022-01-01 (Saturday), because of isoWeek in my systems starts from Sundays.
from datetime import datetime
dt = datetime.now()
print(dt) # 2021-12-27 12:57:57.004108
last_day_of_week = get_ldow(dt)
print(last_day_of_week) # 2022-01-01 00:00:00.000000
How get_ldow(df) could be implemented?
Import of datatime can be tricky.
import datetime
dt = datetime.datetime.today() # 2021-12-27 13:40:10.204296
def get_ldow(dt_input):
return dt_input + datetime.timedelta(days=(6 - dt_input.isoweekday() % 7))
last_day_of_week = get_ldow(dt)
print(last_day_of_week) # 2022-01-01 13:40:10.204296

month begining dates 2 mnths back

I have dates in yyyy-dd-mm in a column(col 1).(type = pandas.core.series.Series and dtypes=datetime64[ns]). I need begining of the month date for 2 months prior(col 2)
col 1 col2
2021-01-07 2020-01-05
I have been trying to use timedelta & relative timedelta , but not working. can anyone help?
Since timedelta does not have months parameter, you can use dateutil module instead:
from dateutil.relativedelta import relativedelta
df['col2'] = df['col1'].apply(lambda x: x - relativedelta(months=2))

Round Pandas date to nearest year/month

I am trying to round a pandas datetime column to its nearest year or month but I cannot figure out how to do it. For instance, this minimal example rounds to the closest hour:
pd.Timestamp.now().round('60min')
What I'd like is a way to replace the '60min' in order to round pd.Timestamp.now() to obtain either 2020-01-01 (for the year case) or 2019-08-01 (for the month case) (note that now() is exactly 2019-07-30 16:41:23.612004 at the time of asking!).
The pandas.Series.dt.round doc suggest a freq argument linking to this page, but trying the months/years options there return this error:
ValueError: is a non-fixed frequency
Any idea what I am missing?
If the column is really DateTime column (check with df.dtypes), you can get the year, month & day with the code below.
df['Year'] = df['Date'].dt.year
df['Month'] = df['Date'].dt.month
df['Day'] = df['Date'].dt.day
df['round_Year'] = df['Date']+ pd.offsets.YearBegin(-1)
rounds off to start of current year. Change -1 to 0 rounds off to start of next year.
df['round_Month'] = df['Date'] + pd.offsets.MonthBegin(-1)
rounds off to start of current Month. Change -1 to 0 rounds off to start of next Month
Example of rounding a Python Timestamp to the nearest half year:
from Pandas import Timestamp
def round_date_to_nearest_half_year(ts: Timestamp) -> Timestamp:
if 4 <= ts.month <=8:
return Timestamp(ts.year, 7, 1)
elif ts.month >=9:
return Timestamp(ts.year+1, 1, 1)
elif ts.month <= 3:
return Timestamp(ts.year, 1, 1)
else:
raise Exception("Logic error.")
Test:
print(round_date_to_nearest_half_year(Timestamp("2022-6-5")))
print(round_date_to_nearest_half_year(Timestamp("2022-7-3")))
print(round_date_to_nearest_half_year(Timestamp("2022-12-15")))
print(round_date_to_nearest_half_year(Timestamp("2023-1-5")))
Out:
2022-07-01 00:00:00
2022-07-01 00:00:00
2023-01-01 00:00:00
2023-01-01 00:00:00

total number of days from current date if we want to know like after 2 weeks, 3 months , 1 year

I want to know the total number of days from current date.
if given date is 2 Feb 2018. and i want to calculate number of days after 2 weeks/3 months/1 year. keeping in mind of leap year or not.
Language - python3
Is there any library in python which give me this.
The dateutil module has a way to do this very conveniently. Sample code:
import datetime
import dateutil
today = datetime.date.today()
delta = dateutil.relativedelta.relativedelta(years=1, months=3, weeks=2)
desired_date = today + delta
desired_date
Output:
datetime.date(2019, 5, 16)

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