Creating a range of dates in Python

Question

I want to create a list of dates  starting with today  and going back an arbitrary number of days  say  in my example 100 days  Is there a better way to do it than this   import datetime  a   datetime datetime today   numdays   100 dateList      for x in range  0  numdays       dateList append a - datetime timedelta days   x   print dateList

User · Answer

Another example that counts forwards or backwards, starting from Sandeep's answer.

from datetime import date, datetime, timedelta
from typing import Sequence
def range_of_dates(start_of_range: date, end_of_range: date) -> Sequence[date]:

    if start_of_range <= end_of_range:
        return [
            start_of_range + timedelta(days=x)
            for x in range(0, (end_of_range - start_of_range).days + 1)
        ]
    return [
        start_of_range - timedelta(days=x)
        for x in range(0, (start_of_range - end_of_range).days + 1)
    ]

start_of_range = datetime.today().date()
end_of_range = start_of_range + timedelta(days=3)
date_range = range_of_dates(start_of_range, end_of_range)
print(date_range)

gives

[datetime.date(2019, 12, 20), datetime.date(2019, 12, 21), datetime.date(2019, 12, 22), datetime.date(2019, 12, 23)]

and

start_of_range = datetime.today().date()
end_of_range = start_of_range - timedelta(days=3)
date_range = range_of_dates(start_of_range, end_of_range)
print(date_range)

gives

[datetime.date(2019, 12, 20), datetime.date(2019, 12, 19), datetime.date(2019, 12, 18), datetime.date(2019, 12, 17)]

Note that the start date is included in the return, so if you want four total dates, use timedelta(days=3)

User · Answer

import datetime     def date generator        cur   base   datetime date today       end    base   datetime timedelta days 100      delta   datetime timedelta days 1      while end gt base           base   base delta         print base  date generator

User · Answer

Based on answers I wrote for myself this   import datetime  print   datetime date today   - datetime timedelta days x   strftime   Y- m- d   for x in range -5  0     Output     2017-12-11    2017-12-10    2017-12-09    2017-12-08    2017-12-07     The difference is that I get the  date  object  not the  datetime datetime  one

User · Answer

I know this has been answered  but I ll put down my answer for historical purposes  and since I think it is straight forward   import numpy as np import datetime as dt listOfDates  date for date in np arange firstDate lastDate dt timedelta days x      Sure it won t win anything like code-golf  but I think it is elegant

User · Answer

You can write a generator function that returns date objects starting from today   import datetime  def date generator      from date   datetime datetime today     while True      yield from date     from date   from date - datetime timedelta days 1    This generator returns dates starting from today and going backwards one day at a time  Here is how to take the first 3 dates    gt  gt  gt  import itertools  gt  gt  gt  dates   itertools islice date generator    3   gt  gt  gt  list dates   datetime datetime 2009  6  14  19  12  21  703890   datetime datetime 2009  6  13  19  12  21  703890   datetime datetime 2009  6  12  19  12  21  703890     The advantage of this approach over a loop or list comprehension is that you can go back as many times as you want   Edit  A more compact version using a generator expression instead of a function   date generator    datetime datetime today   - datetime timedelta days i  for i in itertools count      Usage    gt  gt  gt  dates   itertools islice date generator  3   gt  gt  gt  list dates   datetime datetime 2009  6  15  1  32  37  286765   datetime datetime 2009  6  14  1  32  37  286836   datetime datetime 2009  6  13  1  32  37  286859

User · Answer

Here s a slightly different answer building off of S Lott s answer that gives a list of dates between two dates start and end  In the example below  from the start of 2017 to today   start   datetime datetime 2017 1 1  end   datetime datetime today   daterange    start   datetime timedelta days x  for x in range 0   end-start  days

User · Answer

Marginally better     base   datetime datetime today   date list    base - datetime timedelta days x  for x in range numdays

User · Answer

Here is gist I created  from my own code  this might help   I know the question is too old  but others can use it   https   gist github com 2287345   same thing below   import datetime from time import mktime  def convert date to datetime date object       date tuple   date object timetuple       date timestamp   mktime date tuple      return datetime datetime fromtimestamp date timestamp   def date range how many 7       for x in range 0  how many           some date   datetime datetime today   - datetime timedelta days x          some datetime   convert date to datetime some date date            yield some datetime  def pick two dates how many 7       a   b   convert date to datetime datetime datetime now   date        for each date in date range how many           b   a         a   each date         if a    b              continue         yield b  a

User · Answer

from datetime import datetime  timedelta from dateutil import parser def getDateRange begin  end                    beginDate   parser parse begin      endDate    parser parse end      delta   endDate-beginDate     numdays   delta days   1     dayList    datetime strftime beginDate   timedelta days x     Y m d   for x in range 0  numdays       return dayList

User · Answer

If there are two dates and you need the range try   from dateutil import rrule  parser date1    1995-01-01  date2    1995-02-28  datesx   list rrule rrule rrule DAILY  dtstart parser parse date1   until parser parse date2

User · Answer

Get range of dates between specified start and end date  Optimized for time  amp  space complexity    import datetime  start   datetime datetime strptime  21-06-2014     d- m- Y   end   datetime datetime strptime  07-07-2014     d- m- Y   date generated    start   datetime timedelta days x  for x in range 0   end-start  days    for date in date generated      print date strftime   d- m- Y

User · Answer

Pandas is great for time series in general  and has direct support for date ranges    For example pd date range     import pandas as pd from datetime import datetime  datelist   pd date range datetime today    periods 100  tolist     It also has lots of options to make life easier  For example if you only wanted weekdays  you would just swap in bdate range   See date range documentation  In addition it fully supports pytz timezones and can smoothly span spring autumn DST shifts   EDIT by OP   If you need actual python datetimes  as opposed to Pandas timestamps   import pandas as pd from datetime import datetime  pd date range end   datetime today    periods   100  to pydatetime   tolist     OR  pd date range start  2018-09-09  end  2020-02-02      This uses the  end  parameter to match the original question  but if you want descending dates   pd date range datetime today    periods 100  to pydatetime   tolist

User · Answer

Matplotlib related  from matplotlib dates import drange import datetime  base   datetime date today   end    base   datetime timedelta days 100  delta   datetime timedelta days 1  l   drange base  end  delta

User · Answer

I thought I d throw in my two cents with a simple  and not complete  implementation of a date range  from datetime import date  timedelta  datetime  class DateRange      def   init   self  start  end  step timedelta 1            self start   start         self end   end         self step   step      def   iter   self           start   self start         step   self step         end   self end          n   int  end - start    step          d   start          for   in range n               yield d             d    step      def   contains   self  value           return                self start  lt   value  lt  self end  and                value - self start    self step    timedelta 0

User · Answer

From above answers i created this example for date generator  import datetime date   datetime datetime now   time   date time   def date generator date  delta     counter  0   date   date - datetime timedelta days delta    while counter  lt   delta      yield date     date   date   datetime timedelta days 1      counter   1  for date in date generator date  30      if date date      datetime datetime now   date         start date   datetime datetime combine date  datetime time         end date   datetime datetime combine date  datetime time max     else       start date   datetime datetime combine date  datetime time         end date   datetime datetime combine date  time     print  start date---- gt   start date  end date---- gt   end date

User · Answer

From the title of this question I was expecting to find something like range    that would let me specify two dates and create a list with all the dates in between  That way one does not need to calculate the number of days between those two dates  if one does not know it beforehand   So with the risk of being slightly off-topic  this one-liner does the job   import datetime start date   datetime date 2011  01  01  end date     datetime date 2014  01  01   dates 2011 2013     start date   datetime timedelta n  for n in range int   end date - start date  days      All credits to this answer

User · Answer

A monthly date range generator with datetime and dateutil  Simple and easy to understand   import datetime as dt from dateutil relativedelta import relativedelta  def month range start date  n months           for m in range n months               yield start date   relativedelta months  m

User · Answer

A bit of a late answer I know  but I just had the same problem and decided that Python s internal range function was a bit lacking in this respect so I ve overridden it in a util module of mine   from   builtin   import range as  range from datetime import datetime  timedelta  def range  args       if len args     3          return  range  args      start  stop  step   args     if start  lt  stop          cmp   lambda a  b  a  lt  b         inc   lambda a  a   step     else          cmp   lambda a  b  a  gt  b         inc   lambda a  a - step     output    start      while cmp start  stop           start   inc start          output append start       return output  print range datetime 2011  5  1   datetime 2011  10  1   timedelta days 30

User · Answer

Here s a one liner for bash scripts to get a list of weekdays  this is python 3  Easily modified for whatever  the int at the end is the number of days in the past you want    python -c  import sys datetime  print   n  join   datetime datetime today   - datetime timedelta days x   strftime    Y  m  d    for x in range 0 int sys argv 1    if  datetime datetime today   - datetime timedelta days x   isoweekday   lt 6     10   Here is a variant to provide a start  or rather  end  date  python -c  import sys datetime  print   n  join   datetime datetime strptime sys argv 1     Y  m  d    - datetime timedelta days x   strftime    Y  m  d     for x in range 0 int sys argv 2    if  datetime datetime today   - datetime timedelta days x   isoweekday   lt 6     2015 12 30 10   Here is a variant for arbitrary start and end dates  not that this isn t terribly efficient  but is good for putting in a for loop in a bash script   python -c  import sys datetime  print   n  join   datetime datetime strptime sys argv 1     Y  m  d      datetime timedelta days x   strftime    Y  m  d    for x in range 0 int  datetime datetime strptime sys argv 2      Y  m  d    - datetime datetime strptime sys argv 1      Y  m  d     days   if  datetime datetime strptime sys argv 1      Y  m  d      datetime timedelta days x   isoweekday   lt 6     2015 12 15 2015 12 30

User · Answer

yeah  reinvent the wheel     just search the forum and you ll get something like this    from dateutil import rrule from datetime import datetime  list rrule rrule rrule DAILY count 100 dtstart datetime now

User · Answer

You can also use the day ordinal to make it simpler   def date range start date  end date       for ordinal in range start date toordinal    end date toordinal             yield datetime date fromordinal ordinal    Or as suggested in the comments you can create a list like this   date range         datetime date fromordinal ordinal       for ordinal in range          start date toordinal            end date toordinal

[python] Creating a range of dates in Python

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