[python] finding first day of the month in python

I'm trying to find the first day of the month in python with one condition: if my current date passed the 25th of the month, then the first date variable will hold the first date of the next month instead of the current month. I'm doing the following:

import datetime 
todayDate = datetime.date.today()
if (todayDate - todayDate.replace(day=1)).days > 25:
    x= todayDate + datetime.timedelta(30)
    x.replace(day=1)
    print x
else:
    print todayDate.replace(day=1)

is there a cleaner way for doing this?

Use dateutil.

from datetime import date
from dateutil.relativedelta import relativedelta

today = date.today()
first_day = today.replace(day=1)
if today.day > 25:
    print(first_day + relativedelta(months=1))
else:
    print(first_day)

from datetime import datetime

date_today = datetime.now()
month_first_day = date_today.replace(day=1, hour=0, minute=0, second=0, microsecond=0)
print(month_first_day)

Yes, first set a datetime to the start of the current month.

Second test if current date day > 25 and get a true/false on that. If True then add add one month to the start of month datetime object. If false then use the datetime object with the value set to the beginning of the month.

import datetime 
from dateutil.relativedelta import relativedelta

todayDate = datetime.date.today()
resultDate = todayDate.replace(day=1)

if ((todayDate - resultDate).days > 25):
    resultDate = resultDate + relativedelta(months=1)

print resultDate

You can use dateutil.rrule:

In [1]: from dateutil.rrule import *

In [2]: rrule(DAILY, bymonthday=1)[0].date()
Out[2]: datetime.date(2018, 10, 1)

In [3]: rrule(DAILY, bymonthday=1)[1].date()
Out[3]: datetime.date(2018, 11, 1)

This could be an alternative to Gustavo Eduardo Belduma's answer:

import datetime 
first_day_of_the_month = datetime.date.today().replace(day=1)

First day of next month:

from datetime import datetime

class SomeClassName(models.Model):
    if datetime.now().month == 12:
        new_start_month = 1
    else:
        new_start_month = datetime.now().month + 1

Then we replace the month and the day

    start_date = models.DateField(default=datetime.today().replace(month=new_start_month, day=1, hour=0, minute=0, second=0, microsecond=0))

The arrow module will steer you around and away from subtle mistakes, and it's easier to use that older products.

import arrow

def cleanWay(oneDate):
    if currentDate.date().day > 25:
        return currentDate.replace(months=+1,day=1)
    else:
        return currentDate.replace(day=1)


currentDate = arrow.get('25-Feb-2017', 'DD-MMM-YYYY')
print (currentDate.format('DD-MMM-YYYY'), cleanWay(currentDate).format('DD-MMM-YYYY'))

currentDate = arrow.get('28-Feb-2017', 'DD-MMM-YYYY')
print (currentDate.format('DD-MMM-YYYY'), cleanWay(currentDate).format('DD-MMM-YYYY'))

In this case there is no need for you to consider the varying lengths of months, for instance. Here's the output from this script.

25-Feb-2017 01-Feb-2017
28-Feb-2017 01-Mar-2017

Can be done on the same line using date.replace:

from datetime import datetime

datetime.today().replace(day=1)

My solution to find the first and last day of the current month:

def find_current_month_last_day(today: datetime) -> datetime:
    if today.month == 2:
        return today.replace(day=28)

    if today.month in [4, 6, 9, 11]:
        return today.replace(day=30)

    return today.replace(day=31)


def current_month_first_and_last_days() -> tuple:
    today = datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)
    first_date = today.replace(day=1)
    last_date = find_current_month_last_day(today)
    return first_date, last_date

Use arrow.

import arrow
arrow.utcnow().span('month')[0]