I need to check if a given date is exactly a month ago from today, for example, if today is 01-Nov-2021 then exactly a month ago will be 01-Oct-2021 (not exactly 30 days.)
I wrote a code and it works fine
today = fields.Date.from_string(fields.Date.today())
if today.month == 1:
one_month_ago = today.replace(year=today.year - 1, month=12)
else:
extra_days = 0
while True:
try:
one_month_ago = today.replace(month=today.month - 1, day=today.day -
extra_days)
break
except ValueError:
extra_days += 1
if one_month_ago == given_date:
# do something
else:
# do something
It handles well mostly all the cases but mishandles some cases. For example, the given date is 31-March-2021 and today date is 30-April-2021 and 31-April-2021 will not come to compare. I need my code to run daily and check something. It also mishandles cases of 29-31 January because 29-31 February will not come to compare.
From the given date, you can find the previous month and year and using these two obtained values, find the length of the previous month. The last thing to be done will be to compare the day of the given date with the length of the previous month and accordingly, return the desired date.
Demo:
from datetime import date
from calendar import monthrange
def date_a_month_ago(today):
x = today.month - 1
previous_month = 12 if x == 0 else x
year = today.year - 1 if x == 0 else today.year
last_day_of_previous_month = monthrange(year, previous_month)[1]
day = last_day_of_previous_month if today.day > last_day_of_previous_month else today.day
return date(year, previous_month, day)
# Tests
print(date_a_month_ago(date(2021, 11, 1)))
print(date_a_month_ago(date(2021, 1, 31)))
print(date_a_month_ago(date(2021, 12, 31)))
print(date_a_month_ago(date(2021, 3, 29)))
print(date_a_month_ago(date(2020, 3, 29)))
print(date_a_month_ago(date(2021, 3, 30)))
print(date_a_month_ago(date(2020, 3, 30)))
Output:
2021-10-01
2020-12-31
2021-11-30
2021-02-28
2020-02-29
2021-02-28
2020-02-29
ONLINE DEMO
May be like this:
from typing import Tuple
def last_month(year: int, month: int) -> Tuple[int, int]:
y, m = year, month - 1
if m == 0:
y, m = y - 1, 12
return y, m
def one_month_ago(today: datetime) -> datetime:
y, m = last_month(today.year, today.month)
dt = today.replace(year=y, month=m)
for day in range(today.day, 0, -1):
try:
return dt.replace(day=day)
except ValueError:
...
I did this and it's giving me the required output:
from datetime import date
from calendar import monthrange
def is_one_month(given_date, today):
x = today.month - 1
previous_month = 12 if x == 0 else x
year = today.year - 1 if x == 0 else today.year
last_day_of_previous_month = monthrange(year, previous_month)[1]
day = last_day_of_previous_month if today.day > last_day_of_previous_month else today.day
one_month_ago = date(year, previous_month, day)
if today.month == 2:
if given_date.month == today.month-1 and given_date.year == today.year and given_date.day >= 28:
return 'it is one month before'
if today.month == 4 or today.month == 6 or today.month == 9 or today.month == 11:
if given_date.month == today.month-1 and given_date.day == 31:
return 'it is one month before'
if one_month_ago == given_date:
return 'it is one month before'
else:
return 'it is NOT one month before'
print(is_one_month(date(2021, 1, 30), date(2021, 2, 28)))
Output:
it is one month before
Related
This is my first question here so please forgive and educate on any formatting errors. I am new to Python and going through automate the boring stuff. Decided to expand the date detection project by using the clipboard and formatting some things also. The problem I have is in any operation taken on the year part of the REGEX.
I have commented out my last attempt to validate the year and gave up and changed the REGEX to only find dates from 1000 to 2999 and skipped code validation of the dates.
I now need to validate leap years but I'm back to having to work with the year variable, but once again no operation has any effect.
Basically the problem is I can extract the year value and display it but I cannot modify it or do checks against it.
#! python3
#! detect dates in a block of text
import pyperclip
import re
#!import numpy as np
text = str(pyperclip.paste())
def datedetection(text):
dateRegex = re.compile(
r"""(
(\d|\d\d) #! match day
(/{1}) #! match /
(\d|\d\d) #! match month
(/{1}) #! match /
([1|2][0-9][0-9][0-9]) #! match year
)""",
re.VERBOSE,
)
matches = []
for groups in dateRegex.findall(text):
day = str(groups[1])
slash1 = str(groups[2])
month = str(groups[3])
slash2 = str(groups[4])
year = str(groups[5])
month_range_30 = ["04", "06", "09", "11"]
month_range_31 = ["01", "03", "05", "07", "08", "10", "12"]
month_range_Feb = ["02"]
#!year_range = np.arange(1000, 3000, 1).tolist()
if len(day) == 1:
day = "0" + day
else:
day = day
if len(month) == 1:
month = "0" + month
else:
month = month
if month in month_range_31:
if int(day) > 31:
day = "Too many days in a month with only 31 days."
slash1 = month = slash2 = year = ""
elif month in month_range_30:
if int(day) > 30:
day = "Too many days in a month with only 30 days."
slash1 = month = slash2 = year = ""
elif month in month_range_Feb:
if int(day) > 29:
day = "Too many days in February."
slash1 = month = slash2 = year = ""
elif int(month) > 12:
day = "Found an invalid month."
slash1 = month = slash2 = year = ""
elif month in month_range_Feb:
if (
int(day) == 29
and (int(year) % 4 == 0)
and (int(year) % 400 == 0)
and (int(year) % 100 == 0)
):
day = day
elif month in month_range_Feb:
if (
int(day) == 29
and (int(year) % 4 == 0)
and (int(year) % 100 != 0)
):
day = "Found an invalid leap year."
slash1 = month = slash2 = year = ""
#!elif year not in year_range:
#!day = "Year is out of range."
#!slash1 = month = slash2 = year = ""
dates = "".join([day, slash1, month, slash2, year])
matches.append(dates)
if len(matches) > 0:
pyperclip.copy("\n".join(matches))
print("Copied to clipboard:")
print("\n".join(matches))
else:
print("No dates found.")
datedetection(text)
In my approach to this project, I considered validating the days, months, and year ranges as part of the regular expression. I then defined functions to check for the leap year, and validate the number of days according to the months.
I found that way simpler and easier to understand and follow. As below:
dateRegex = re.compile(r'([0-3][0-9])/([0-1][0-9])/([1-2][0-9]{3})')
def is_leap_year(year):
year = int(year)
if year % 4 == 0:
if year % 100 == 0:
return year % 400 == 0
else:
return True
else:
return False
def is_valid_date(day, month, year):
if month == '02':
if is_leap_year(year):
return int(day) <= 29
else:
return int(day) <= 28
elif month in ['04', '06', '09', '11']:
return int(day) <= 30
else:
return int(day) <= 31
You can find the rest of my code below.
https://gist.github.com/alialbusaidi/f56e4c9342f622434f8bff0549f94884
The problem was the operations before the year operations. The day and month operations were overwriting the year values. Not entirely sure how or why at this point, but moving the year code above the day and month code has started to fix the issue.
hay guys i need to write a program that i give a date and then i give numbers of days and then i get a new date ( the numbers of days can be + or - ). i will be happy if someone help me. (about the first and second line , i just need them in the output)
specific_date =input('Enter a date:')
numofdays=input("Enter number of days:")
from datetime import datetime, timedelta
specific_date = datetime(day/month/year)
new_date = specific_date + timedelta(numofdays)
if (year % 400 == 0):
leap_year = True
elif (year % 100 == 0):
leap_year = False
elif (year % 4 == 0):
leap_year = True
else:
leap_year = False
month=['1','2','3','4','5','6','7','8','9','10','11','12']
if month in (1, 3, 5, 7, 8, 10, 12):
day in [1,31]
elif month == 2:
if leap_year:
day in[1,29]
else:
day in[1,28]
if month in (4,6,9,11):
day in [1,30]
Got set some course homework to do this. It was going all good until I noticed one of the test cases werent working, trying to get the days between 2012-1-1 and 2013-1-1.
I guessed it would be 366, extra day as 2012 was a leap year. This code seems to be guessing 365, my tutor has marked the answer down as 360.
He said something about "just make all months 30 days", so I'm thinking his 360 is something related to that? Anyway, that doesn't excuse my code guessing 365 when it should be guessing 366.
Output is as shows
Test case passed! CONGRATULATIONS
Test with data: (2012, 1, 1, 2013, 1, 1) failed passed 365 should of passed 360
Test case passed! CONGRATULATIONS
daysOfMonths = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ]
def is_leap_year(year):
return year % 4 == 0 and (year % 100 != 0 or year % 400 == 0)
def get_days_from_year(year):
days = year * 365
i = 0
while i < year:
i += 1
if is_leap_year(i):
days += 1
return days
def get_days_from_month(month, year):
days = 0
i = 0
while i < month:
if i == 1 and is_leap_year(year):
days += daysOfMonths[i] + 1
else:
days += daysOfMonths[i]
i += 1
return days
def get_days_from_date(year, month, day):
days_in_year = get_days_from_year(year)
days_in_month = get_days_from_month(month - 1, year)
days = days_in_year + days_in_month + day
return days
def daysBetweenDates(year1, month1, day1, year2, month2, day2):
first_date_days = get_days_from_date(year1, month1, day1)
second_date_days = get_days_from_date(year2, month2, day2)
if first_date_days > second_date_days:
return first_date_days - second_date_days
else:
return second_date_days - first_date_days
def test():
test_cases = [((2012,9,30,2012,10,30),30),
((2012,1,1,2013,1,1),360),
((2012,9,1,2012,9,4),3)]
for (args, answer) in test_cases:
result = daysBetweenDates(*args)
if result != answer:
print("Test with data:", args, "failed passed", result, "should of passed", answer)
else:
print("Test case passed! CONGRATULATIONS")
test()
You are incrementing i in the wrong place. You have:
while i < year:
i += 1
if is_leap_year(i):
days += 1
but should be:
while i < year:
if is_leap_year(i):
days += 1
i += 1
because of this, your leap years are all off by 1 (2011 vs 2012, 2015 vs 2016, etc.)
He said something about "just make all months 30 days", so
def get_range(year1,month1,day1,year2,month2,day2):
"""
assumes all months have 30 days, with no leap years
~ for some weird reason i dont understand
(probably so you dont use builtin datetime)
"""
days_difference = (year2-year1)*360
days_difference += (month2-month1)*30
return days_difference + day2-day1
print(get_range(2012, 1, 1, 2013, 1, 1))
if you want to get the actual number of days between two dates
from datetime import datetime
def get_real_range(year1,month1,day1,year2,month2,day2):
return (datetime(year2,month2,day2) - datetime(year1,month1,day1)).days
I am trying to program a calendar that checks how many days from now/ ago (past and present) from raw_input. I need a loop that counts the days through the current year and adds it to a variable called: Total_days and this loop has to go through each year until it hits the current date that the code ran on. The end result is that the output gives you the date you entered in a complete sentence: eg. "10/08/1700 was ___ days ago" Basically my teacher explained that the past days has to add up until it hits that certain date using a loop(loops are required. This is an assignment, i cant use any other functions like delta, but loops and datetime stuff is good!) and then for the future it has to say how many days from now until that futuristic date happens using loops. I am very stumped and i need your guys' help.
Heres what i got so far:
import datetime
input_date = raw_input("Enter in full format (mm/dd/yyyy):")
year = input_date[6:10]
yeara = int(year)
montha = int(input_date[1:2])
daya = int(input_date[4:5])
from datetime import datetime
from datetime import date
now = datetime.now()
year = now.year
month = now.month
day = now.day
def isleapYear(year):
if year % 4 == 0:
check = True
if year % 100 == 0:
check = False
if year % 400 == 0:
check = True
total_days = 0
n = 12
moNum = [0,31,28,31,30,31,30,31,31,30,31,30,31]
while n > montha:
if yeara > year:
if year == isleapYear(year):
total_days += 366
elif year != isleapYear(year):
total_days += 365
if montha == month:
break
total_days += int(moNum[n])
if n == 02:
if isleapYear(year) == True:
total_days += 1
n -= 1
ny = 365
h = total_days
if yeara > year:
if year == isleapYear(year):
total_days += 366
elif year != isleapYear(year):
total_days += 365
if yeara>year:
time = "future"
if yeara<year:
time = "past"
if yeara==year:
if montha>month:
time = "future"
if montha<month:
time = past
if montha == month:
if daya>day:
time = "future"
if daya<day:
time = "past"
if daya==day:
time = "present"
print str(h.days) + " days in the " + str(time)
Thanks for helping out! i appreciate your help :)
Must you use a loop? Else, you can build from the following:
refdatestr = "2010/08/23"
refdate = datetime.strptime(refdatestr, "%Y/%m/%d")
now = datetime.now()
difference_days = (now-refdate).days
difference_days is a datetime.timedelta object. If refdate (or refdatestr) was in the future, this would be negative.
Here is an updated code, with everything fixed:
import datetime
input_date = raw_input("Enter in full format (mm/dd/yyyy):")
year = input_date[6:10]
yeara = int(year)
montha = int(input_date[1:2])
daya = int(input_date[4:5])
from datetime import datetime
from datetime import date
now = datetime.now()
year = now.year
month = now.month
day = now.day
def isleapYear(year):
if year % 4 == 0:
check = True
if year % 100 == 0:
check = False
if year % 400 == 0:
check = True
end_date = input_date
start_date = now
delta = date(year,month,day)
delta2 = date(yeara,montha,daya)
h = delta-delta2
if yeara>year:
time = "future"
if yeara<year:
time = "past"
if yeara==year:
if montha>month:
time = "future"
if montha<month:
time = past
if montha == month:
if daya>day:
time = "future"
if daya<day:
time = "past"
if daya==day:
time = "present"
print str(h.days) + " in the " + str(time)
The most important thing that you forgot is that there are functions in datetime that will automatically find the number of days till the input...
Hope this helps!!!
import datetime
def main():
date_string = input('Enter a date in mm/dd/yy format: ')
date_list = date_string.split('/')
month = int(date_list[0])
day = int(date_list[1])
year = int(date_list[2])
while month < 1 or month > 12:
print('Month entered is out of range')
date_string = input('Re-enter a date in mm/dd/yy format: ')
date_list = date_string.split('/')
month = int(date_list[0])
day = int(date_list[1])
year = int(date_list[2])
while day < 1 or day > 31:
print('Day entered is out of range')
date_string = input('Re-enter a date in mm/dd/yy format: ')
date_list = date_string.split('/')
month = int(date_list[0])
day = int(date_list[1])
year = int(date_list[2])
while year != 13:
print('Year does not represent 2013')
date_string = input('Re-enter a date in mm/dd/yy format: ')
date_list = date_string.split('/')
month = int(date_list[0])
day = int(date_list[1])
year = int(date_list[2])
print(month, day, year)
main()
When I run the program and enter months and days that are invalid, it progresses down until the year validation and will keep posting that prompt even if the input is invalid for one of the other inputs.
You could arrange this differently:
while True:
date_string = input('Enter a date in mm/dd/yy format: ')
date_list = date_string.split('/')
month = int(date_list[0])
day = int(date_list[1])
year = int(date_list[2])
if month < 1 or month > 12:
print('Month entered is out of range')
elif day < 1 or day > 31:
print('Day entered is out of range')
elif year != 13:
print('Year does not represent 2013')
else:
break
print(month, day, year)
Start again.
You don't want three little while loops. You want one big while loops ( while not success ) with three if statement to make the three checks and if any one fails, set success to false.