Getting today's date in YYYY-MM-DD in Python? - python

Is there a nicer way than the following to return today's date in the YYYY-MM-DD format?
str(datetime.datetime.today()).split()[0]

Use strftime:
>>> from datetime import datetime
>>> datetime.today().strftime('%Y-%m-%d')
'2021-01-26'
To also include a zero-padded Hour:Minute:Second at the end:
>>> datetime.today().strftime('%Y-%m-%d %H:%M:%S')
'2021-01-26 16:50:03'
To get the UTC date and time:
>>> datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S')
'2021-01-27 00:50:03'

You can use datetime.date.today() and convert the resulting datetime.date object to a string:
from datetime import date
today = str(date.today())
print(today) # '2017-12-26'

I always use the isoformat() method for this.
from datetime import date
today = date.today().isoformat()
print(today) # '2018-12-05'
Note that this also works on datetime objects if you need the time in the standard ISO 8601 format as well.
from datetime import datetime
now = datetime.today().isoformat()
print(now) # '2018-12-05T11:15:55.126382'

Very late answer, but you can simply use:
import time
today = time.strftime("%Y-%m-%d")
# 2023-02-08

Datetime is just lovely if you like remembering funny codes. Wouldn't you prefer simplicity?
>>> import arrow
>>> arrow.now().format('YYYY-MM-DD')
'2017-02-17'
This module is clever enough to understand what you mean.
Just do pip install arrow.
Addendum: In answer to those who become exercised over this answer let me just say that arrow represents one of the alternative approaches to dealing with dates in Python. That's mostly what I meant to suggest.

Are you working with Pandas?
You can use pd.to_datetime from the pandas library. Here are various options, depending on what you want returned.
import pandas as pd
pd.to_datetime('today') # pd.to_datetime('now')
# Timestamp('2019-03-27 00:00:10.958567')
As a python datetime object,
pd.to_datetime('today').to_pydatetime()
# datetime.datetime(2019, 4, 18, 3, 50, 42, 587629)
As a formatted date string,
pd.to_datetime('today').isoformat()
# '2019-04-18T04:03:32.493337'
# Or, `strftime` for custom formats.
pd.to_datetime('today').strftime('%Y-%m-%d')
# '2019-03-27'
To get just the date from the timestamp, call Timestamp.date.
pd.to_datetime('today').date()
# datetime.date(2019, 3, 27)
Aside from to_datetime, you can directly instantiate a Timestamp object using,
pd.Timestamp('today') # pd.Timestamp('now')
# Timestamp('2019-04-18 03:43:33.233093')
pd.Timestamp('today').to_pydatetime()
# datetime.datetime(2019, 4, 18, 3, 53, 46, 220068)
If you want to make your Timestamp timezone aware, pass a timezone to the tz argument.
pd.Timestamp('now', tz='America/Los_Angeles')
# Timestamp('2019-04-18 03:59:02.647819-0700', tz='America/Los_Angeles')
Yet another date parser library: Pendulum
This one's good, I promise.
If you're working with pendulum, there are some interesting choices. You can get the current timestamp using now() or today's date using today().
import pendulum
pendulum.now()
# DateTime(2019, 3, 27, 0, 2, 41, 452264, tzinfo=Timezone('America/Los_Angeles'))
pendulum.today()
# DateTime(2019, 3, 27, 0, 0, 0, tzinfo=Timezone('America/Los_Angeles'))
Additionally, you can also get tomorrow() or yesterday()'s date directly without having to do any additional timedelta arithmetic.
pendulum.yesterday()
# DateTime(2019, 3, 26, 0, 0, 0, tzinfo=Timezone('America/Los_Angeles'))
pendulum.tomorrow()
# DateTime(2019, 3, 28, 0, 0, 0, tzinfo=Timezone('America/Los_Angeles'))
There are various formatting options available.
pendulum.now().to_date_string()
# '2019-03-27'
pendulum.now().to_formatted_date_string()
# 'Mar 27, 2019'
pendulum.now().to_day_datetime_string()
# 'Wed, Mar 27, 2019 12:04 AM'
Rationale for this answer
A lot of pandas users stumble upon this question because they believe it is a python question more than a pandas one. This answer aims to be useful to folks who are already using these libraries and would be interested to know that there are ways to achieve these results within the scope of the library itself.
If you are not working with pandas or pendulum already, I definitely do not recommend installing them just for the sake of running this code! These libraries are heavy and come with a lot of plumbing under the hood. It is not worth the trouble when you can use the standard library instead.

from datetime import datetime
date = datetime.today().date()
print(date)

Use f-strings, they are usually the best choice for any text-variable mix:
from datetime import date
print(f'{date.today():%Y-%m-%d}')
Taken from Python f-string formatting not working with strftime inline which has the official links as well.

If you need e.g. pacific standard time (PST) you can do
from datetime import datetime
import pytz
tz = pytz.timezone('US/Pacific')
datetime.now(tz).strftime('%Y-%m-%d %H:%M:%S')
# '2021-09-02 10:21:41'

my code is a little complicated but I use it a lot
strftime("%y_%m_%d", localtime(time.time()))
reference:'https://strftime.org/
you can look at the reference to make anything you want
for you what YYYY-MM-DD just change my code to:
strftime("%Y-%m-%d", localtime(time.time()))

This works:
from datetime import date
today =date.today()
Output in this time: 2020-08-29
Additional:
this_year = date.today().year
this_month = date.today().month
this_day = date.today().day
print(today)
print(this_year)
print(this_month)
print(this_day)

To get day number from date is in python
for example:19-12-2020(dd-mm-yyy)order_date
we need 19 as output
order['day'] = order['Order_Date'].apply(lambda x: x.day)

Related

Calculate hours difference between timezone and UTC based timezone name in following format: America/New_York

I have a library which returns the timezone of a location in the format: America/New_York. Based on that timezone name, I want to calculate the hours between that time zone and UTC, taking into account daylight savings time and all. I'm using Python.
My first idea was to use the Google python library and search for 'America/New_York time' but that only gave me back a list of urls which I could visit to get the info myself. It would be awesome if I could get the current time seen if I were to manually search 'America/New_York time' into google, right into my program.
I'm sure this question has been asked before, but I am new to stack overflow and python so help is appreciated.
Thanks!
The offset from UTC depends on the date (since daylight saving time may or may not be in effect). So you need to provide a datetime for the comparison.
ZoneInfo.utcoffset will return a timedelta object directly.
>>> from zoneinfo import ZoneInfo
>>> from datetime import datetime
>>> ZoneInfo("America/New_York").utcoffset(datetime(2021, 10, 23)) #EDT
datetime.timedelta(days=-1, seconds=72000)
>>> ZoneInfo("America/New_York").utcoffset(datetime(2021, 11, 15)) #EST
datetime.timedelta(days=-1, seconds=68400)
>>> ZoneInfo("Asia/Tokyo").utcoffset(datetime(2021, 10, 23))
datetime.timedelta(seconds=32400)
Not a complete answer, but maybe you could implement a dictionary that connects these format to the normal format with three letters. With this you can then use datetime and pytz to make the rest. If you don't have too many possible outputs in the current format this would be feasible, otherwise of course not.
>>> from datetime import datetime, timedelta
>>> from datetime import timezone
>>> from zoneinfo import ZoneInfo
>>> dt1 = datetime(2020, 11, 1, 8, tzinfo=timezone.utc)
>>> dt2 = datetime(2020, 11, 1, 8, tzinfo=ZoneInfo("America/New_York"))
>>> dt2 - dt1
datetime.timedelta(seconds=18000)
>>>
Note that the difference will be four for five hours depending on whether daylight saving time is in effect or not.

Strange behavior with pandas timestamp to posix conversion

I do the following operations:
Convert string datetime in pandas dataframe to python datetime via apply(strptime)
Convert datetime to posix timestamp via .timestamp() method
If I revert posix back to datetime with .fromtimestamp() I obtain different datetime
It differs by 3 hours which is my timezone (I'm at UTC+3 now), so I suppose it is a kind of timezone issue. Also I understand that in apply it implicitly converts to pandas.Timestamp, but I don't understand the difference in this case.
What is the reason for such strange behavior and what should I do to avoid it? Actually in my project I need to compare this pandas timestamps with correct poxis timestamps and now it works wrong.
Below is dummy reproducible example:
df = pd.DataFrame(['2018-03-03 14:30:00'], columns=['c'])
df['c'] = df['c'].apply(lambda x: datetime.datetime.strptime(x, '%Y-%m-%d %H:%M:%S'))
dt = df['c'].iloc[0]
dt
>> Timestamp('2018-03-03 14:30:00')
datetime.datetime.fromtimestamp(dt.timestamp())
>> datetime.datetime(2018, 3, 3, 17, 30)
First, I suggest using the np.timedelta64 dtype when working with pandas. In this case it makes the reciprocity simple.
pd.to_datetime('2018-03-03 14:30:00').value
#1520087400000000000
pd.to_datetime(pd.to_datetime('2018-03-03 14:30:00').value)
#Timestamp('2018-03-03 14:30:00')
The issue with the other methods is that POSIX has UTC as the origin, but fromtimestamp returns the local time. If your system isn't UTC compliant, then we get issues. The following methods will work to remedy this:
from datetime import datetime
import pytz
dt
#Timestamp('2018-03-03 14:30:00')
# Seemingly problematic:
datetime.fromtimestamp(dt.timestamp())
#datetime.datetime(2018, 3, 3, 9, 30)
datetime.fromtimestamp(dt.timestamp(), tz=pytz.utc)
#datetime.datetime(2018, 3, 3, 14, 30, tzinfo=<UTC>)
datetime.combine(dt.date(), dt.timetz())
#datetime.datetime(2018, 3, 3, 14, 30)
mytz = pytz.timezone('US/Eastern') # Use your own local timezone
datetime.fromtimestamp(mytz.localize(dt).timestamp())
#datetime.datetime(2018, 3, 3, 14, 30)
An answer with the to_datetime function:
df = pd.DataFrame(['2018-03-03 14:30:00'], columns=['c'])
df['c'] = pd.to_datetime(df['c'].values, dayfirst=False).tz_localize('Your/Timezone')
When working with date, you should always put a timezone it is easier after to work with.
It does not explain the difference between the datetime in pandas and alone.

How to convert a timezone aware string to datetime in Python without dateutil?

I have to convert a timezone-aware string like "2012-11-01T04:16:13-04:00" to a Python datetime object.
I saw the dateutil module which has a parse function, but I don't really want to use it as it adds a dependency.
So how can I do it? I have tried something like the following, but with no luck.
datetime.datetime.strptime("2012-11-01T04:16:13-04:00", "%Y-%m-%dT%H:%M:%S%Z")
As of Python 3.7, datetime.datetime.fromisoformat() can handle your format:
>>> import datetime
>>> datetime.datetime.fromisoformat('2012-11-01T04:16:13-04:00')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=72000)))
In older Python versions you can't, not without a whole lot of painstaking manual timezone defining.
Python does not include a timezone database, because it would be outdated too quickly. Instead, Python relies on external libraries, which can have a far faster release cycle, to provide properly configured timezones for you.
As a side-effect, this means that timezone parsing also needs to be an external library. If dateutil is too heavy-weight for you, use iso8601 instead, it'll parse your specific format just fine:
>>> import iso8601
>>> iso8601.parse_date('2012-11-01T04:16:13-04:00')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=<FixedOffset '-04:00'>)
iso8601 is a whopping 4KB small. Compare that tot python-dateutil's 148KB.
As of Python 3.2 Python can handle simple offset-based timezones, and %z will parse -hhmm and +hhmm timezone offsets in a timestamp. That means that for a ISO 8601 timestamp you'd have to remove the : in the timezone:
>>> from datetime import datetime
>>> iso_ts = '2012-11-01T04:16:13-04:00'
>>> datetime.strptime(''.join(iso_ts.rsplit(':', 1)), '%Y-%m-%dT%H:%M:%S%z')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=datetime.timezone(datetime.timedelta(-1, 72000)))
The lack of proper ISO 8601 parsing is being tracked in Python issue 15873.
Here is the Python Doc for datetime object using dateutil package..
from dateutil.parser import parse
get_date_obj = parse("2012-11-01T04:16:13-04:00")
print get_date_obj
There are two issues with the code in the original question: there should not be a : in the timezone and the format string for "timezone as an offset" is lower case %z not upper %Z.
This works for me in Python v3.6
>>> from datetime import datetime
>>> t = datetime.strptime("2012-11-01T04:16:13-0400", "%Y-%m-%dT%H:%M:%S%z")
>>> print(t)
2012-11-01 04:16:13-04:00
You can convert like this.
date = datetime.datetime.strptime('2019-3-16T5-49-52-595Z','%Y-%m-%dT%H-%M-%S-%f%z')
date_time = date.strftime('%Y-%m-%dT%H:%M:%S.%fZ')
You can create a timezone unaware object and replace the tzinfo and make it a timezone aware DateTime object later.
from datetime import datetime
import pytz
unware_time = datetime.strptime("2012-11-01 04:16:13", "%Y-%m-%d %H:%M:%S")
aware_time = unaware_time.replace(tzinfo=pytz.UTC)
I'm new to Python, but found a way to convert
2017-05-27T07:20:18.000-04:00
to
2017-05-27T07:20:18 without downloading new utilities.
from datetime import datetime, timedelta
time_zone1 = int("2017-05-27T07:20:18.000-04:00"[-6:][:3])
>>returns -04
item_date = datetime.strptime("2017-05-27T07:20:18.000-04:00".replace(".000", "")[:-6], "%Y-%m-%dT%H:%M:%S") + timedelta(hours=-time_zone1)
I'm sure there are better ways to do this without slicing up the string so much, but this got the job done.
This suggestion for using dateutil by Mohideen bin Mohammed definitely is the best solution even if it does a require a small library. having used the other approaches there prone to various forms of failure. Here's a nice function for this.
from dateutil.parser import parse
def parse_date_convert(date, fmt=None):
if fmt is None:
fmt = '%Y-%m-%d %H:%M:%S' # Defaults to : 2022-08-31 07:47:30
get_date_obj = parse(str(date))
return str(get_date_obj.strftime(fmt))
dates = ['2022-08-31T07:47:30Z','2022-08-31T07:47:29.098Z','2017-05-27T07:20:18.000-04:00','2012-11-01T04:16:13-04:00']
for date in dates:
print(f'Before: {date} After: {parse_date_convert(date)}')
Results:
Before: 2022-08-31T07:47:30Z After: 2022-08-31 07:47:30
Before: 2022-08-31T07:47:29.098Z After: 2022-08-31 07:47:29
Before: 2017-05-27T07:20:18.000-04:00 After: 2017-05-27 07:20:18
Before: 2012-11-01T04:16:13-04:00 After: 2012-11-01 04:16:13
Having tried various forms such as slicing split replacing the T Z like this:
dates = ['2022-08-31T07:47:30Z','2022-08-31T07:47:29.098Z','2017-05-27T07:20:18.000-04:00','2012-11-01T04:16:13-04:00']
for date in dates:
print(f'Before: {date} After: {date.replace("T", " ").replace("Z", "")}')
You still are left with subpar results. like the below
Before: 2022-08-31T07:47:30Z After: 2022-08-31 07:47:30
Before: 2022-08-31T07:47:29.098Z After: 2022-08-31 07:47:29.098
Before: 2017-05-27T07:20:18.000-04:00 After: 2017-05-27 07:20:18.000-04:00
Before: 2012-11-01T04:16:13-04:00 After: 2012-11-01 04:16:13-04:00

In Python, how do you convert seconds since epoch to a `datetime` object?

The time module can be initialized using seconds since epoch:
>>> import time
>>> t1=time.gmtime(1284286794)
>>> t1
time.struct_time(tm_year=2010, tm_mon=9, tm_mday=12, tm_hour=10, tm_min=19,
tm_sec=54, tm_wday=6, tm_yday=255, tm_isdst=0)
Is there an elegant way to initialize a datetime.datetime object in the same way?
datetime.datetime.fromtimestamp will do, if you know the time zone, you could produce the same output as with time.gmtime
>>> datetime.datetime.fromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 11, 19, 54)
or
>>> datetime.datetime.utcfromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 10, 19, 54)
Seconds since epoch to datetime to strftime:
>>> ts_epoch = 1362301382
>>> ts = datetime.datetime.fromtimestamp(ts_epoch).strftime('%Y-%m-%d %H:%M:%S')
>>> ts
'2013-03-03 01:03:02'
From the docs, the recommended way of getting a timezone aware datetime object from seconds since epoch is:
Python 3:
from datetime import datetime, timezone
datetime.fromtimestamp(timestamp, timezone.utc)
Python 2, using pytz:
from datetime import datetime
import pytz
datetime.fromtimestamp(timestamp, pytz.utc)
Note that datetime.datetime.fromtimestamp(timestamp) and .utcfromtimestamp(timestamp) fail on windows for dates before Jan. 1, 1970 while negative unix timestamps seem to work on unix-based platforms. The docs say this:
"This may raise ValueError, if the timestamp is out of the range of
values supported by the platform C gmtime() function. It’s common for
this to be restricted to years in 1970 through 2038"
See also Issue1646728
For those that want it ISO 8601 compliant, since the other solutions do not have the T separator nor the time offset (except Meistro's answer):
from datetime import datetime, timezone
result = datetime.fromtimestamp(1463288494, timezone.utc).isoformat('T', 'microseconds')
print(result) # 2016-05-15T05:01:34.000000+00:00
Note, I use fromtimestamp because if I used utcfromtimestamp I would need to chain on .astimezone(...) anyway to get the offset.
If you don't want to go all the way to microseconds you can choose a different unit with the
isoformat() method.

Python: Figure out local timezone

I want to compare UTC timestamps from a log file with local timestamps. When creating the local datetime object, I use something like:
>>> local_time=datetime.datetime(2010, 4, 27, 12, 0, 0, 0,
tzinfo=pytz.timezone('Israel'))
I want to find an automatic tool that would replace thetzinfo=pytz.timezone('Israel') with the current local time zone.
Any ideas?
In Python 3.x, local timezone can be figured out like this:
>>> import datetime
>>> print(datetime.datetime.now(datetime.timezone.utc).astimezone().tzinfo)
AEST
It's a tricky use of datetime's code .
For python < 3.6, you'll need
>>> import datetime
>>> print(datetime.datetime.now(datetime.timezone(datetime.timedelta(0))).astimezone().tzinfo)
AEST
Try dateutil, which has a tzlocal type that does what you need.
to compare UTC timestamps from a log file with local timestamps.
It is hard to find out Olson TZ name for a local timezone in a portable manner. Fortunately, you don't need it to perform the comparison.
tzlocal module returns a pytz timezone corresponding to the local timezone:
from datetime import datetime
import pytz # $ pip install pytz
from tzlocal import get_localzone # $ pip install tzlocal
tz = get_localzone()
local_dt = tz.localize(datetime(2010, 4, 27, 12, 0, 0, 0), is_dst=None)
utc_dt = local_dt.astimezone(pytz.utc) #NOTE: utc.normalize() is unnecessary here
Unlike other solutions presented so far the above code avoids the following issues:
local time can be ambiguous i.e., a precise comparison might be impossible for some local times
utc offset can be different for the same local timezone name for dates in the past. Some libraries that support timezone-aware datetime objects (e.g., dateutil) fail to take that into account
Note: to get timezone-aware datetime object from a naive datetime object, you should use*:
local_dt = tz.localize(datetime(2010, 4, 27, 12, 0, 0, 0), is_dst=None)
instead of:
#XXX fails for some timezones
local_dt = datetime(2010, 4, 27, 12, 0, 0, 0, tzinfo=tz)
*is_dst=None forces an exception if given local time is ambiguous or non-existent.
If you are certain that all local timestamps use the same (current) utc offset for the local timezone then you could perform the comparison using only stdlib:
# convert a naive datetime object that represents time in local timezone to epoch time
timestamp1 = (datetime(2010, 4, 27, 12, 0, 0, 0) - datetime.fromtimestamp(0)).total_seconds()
# convert a naive datetime object that represents time in UTC to epoch time
timestamp2 = (datetime(2010, 4, 27, 9, 0) - datetime.utcfromtimestamp(0)).total_seconds()
timestamp1 and timestamp2 can be compared directly.
Note:
timestamp1 formula works only if the UTC offset at epoch (datetime.fromtimestamp(0)) is the same as now
fromtimestamp() creates a naive datetime object in the current local timezone
utcfromtimestamp() creates a naive datetime object in UTC.
I was asking the same to myself, and I found the answer in 1:
Take a look at section 8.1.7: the format "%z" (lowercase, the Z uppercase returns also the time zone, but not in the 4-digit format, but in the form of timezone abbreviations, like in [3]) of strftime returns the form "+/- 4DIGIT" that is standard in email headers (see section 3.3 of RFC 2822, see [2], which obsoletes the other ways of specifying the timezone for email headers).
So, if you want your timezone in this format, use:
time.strftime("%z")
[1] http://docs.python.org/2/library/datetime.html
[2] https://www.rfc-editor.org/rfc/rfc2822#section-3.3
[3] Timezone abbreviations: http://en.wikipedia.org/wiki/List_of_time_zone_abbreviations , only for reference.
The following appears to work for 3.7+, using standard libs:
from datetime import timedelta
from datetime import timezone
import time
def currenttz():
if time.daylight:
return timezone(timedelta(seconds=-time.altzone),time.tzname[1])
else:
return timezone(timedelta(seconds=-time.timezone),time.tzname[0])
First get pytz and tzlocal modules
pip install pytz tzlocal
then
from tzlocal import get_localzone
local = get_localzone()
then you can do things like
from datetime import datetime
print(datetime.now(local))
Here's a way to get the local timezone using only the standard library, (only works in a *nix environment):
>>> '/'.join(os.path.realpath('/etc/localtime').split('/')[-2:])
'Australia/Sydney'
You can use this to create a pytz timezone:
>>> import pytz
>>> my_tz_name = '/'.join(os.path.realpath('/etc/localtime').split('/')[-2:])
>>> my_tz = pytz.timezone(my_tz_name)
>>> my_tz
<DstTzInfo 'Australia/Sydney' LMT+10:05:00 STD>
...which you can then apply to a datetime:
>>> import datetime
>>> now = datetime.datetime.now()
>>> now
datetime.datetime(2014, 9, 3, 9, 23, 24, 139059)
>>> now.replace(tzinfo=my_tz)
>>> now
datetime.datetime(2014, 9, 3, 9, 23, 24, 139059, tzinfo=<DstTzInfo 'Australia/Sydney' LMT+10:05:00 STD>)
Here's a slightly more concise version of #vbem's solution:
from datetime import datetime as dt
dt.utcnow().astimezone().tzinfo
The only substantive difference is that I replaced datetime.datetime.now(datetime.timezone.utc) with datetime.datetime.utcnow(). For brevity, I also aliased datetime.datetime as dt.
For my purposes, I want the UTC offset in seconds. Here's what that looks like:
dt.utcnow().astimezone().utcoffset().total_seconds()
Avoiding non-standard module (seems to be a missing method of datetime module):
from datetime import datetime
utcOffset_min = int(round((datetime.now() - datetime.utcnow()).total_seconds())) / 60 # round for taking time twice
utcOffset_h = utcOffset_min / 60
assert(utcOffset_min == utcOffset_h * 60) # we do not handle 1/2 h timezone offsets
print 'Local time offset is %i h to UTC.' % (utcOffset_h)
To create an ISO formatted string that includes the ISO representation of your local time zone in Israel (+04:00) :
on a server in Israel:
>>> datetime.now(datetime.now().astimezone().tzinfo).isoformat()
'2021-09-07T01:02.030042+04:00'
This will create a "timezone aware" date object that will compare to any other datetime object in UTC or local time appropriately. But the time zone ISO representation (and the date/time string itself) will change if you ran this on a server in San Francisco at the exact same time, as I did:
on a server in San Francisco, CA, USA (Pacific):
>>> datetime.now(datetime.now().astimezone().tzinfo).isoformat()
'2021-09-06T14:01:02.030042-07:00'
The datetime objects in in both cases would be compatible with each other. So if you subtracted them you'd get a time delta of 0:
On a server anywhere in Python3.6+:
>>> (datetime.fromisoformat('2021-09-06T14:01:02.030042-07:00') -
... datetime.fromisoformat('2021-09-07T01:01:02.030042+04:00'))
datetime.timedelta(0)
Based on Thoku's answer above, here's an answer that resolves the time zone to the nearest half hour (which is relevant for some timezones eg South Australia's) :
from datetime import datetime
round((round((datetime.now()-datetime.utcnow()).total_seconds())/1800)/2)
Based on J. F. Sebastian's answer, you can do this with the standard library:
import time, datetime
local_timezone = datetime.timezone(datetime.timedelta(seconds=-time.timezone))
Tested in 3.4, should work on 3.4+
You may be happy with pendulum
>>> pendulum.datetime(2015, 2, 5, tz='local').timezone.name
'Israel'
Pendulum has a well designed API for manipulating dates. Everything is TZ-aware.
I have also been looking for a simple way to read the local host configuration and get timezone aware local_time based on it. As of python 3.6+ the simplest approach is use dateutil.tz which will read /etc/localtime and assist in getting timezone aware datetime object.
Here is more info on it: https://dateutil.readthedocs.io/en/stable/tz.html
The implementation to accomplish what you're looking for is as follows:
from datetime import datetime
from dateutil import tz
local_time = datetime.now(tz.gettz())
This will provide you the following local_time:
2019-10-18 13:41:06.624536-05:00
Additional Resources I used in researching this topic:
Paul Ganssle Presentation about time zones:
https://www.youtube.com/watch?v=l4UCKCo9FWY
pytz: The Fastest Footgun in the West
https://blog.ganssle.io/articles/2018/03/pytz-fastest-footgun.html
I want to compare UTC timestamps from a log file with local timestamps
If this is your intent, then I wouldn't worry about specifying specific tzinfo parameters or any additional external libraries. Since Python 3.5, the built in datetime module is all you need to create a UTC and a local timestamp automatically.
import datetime
f = "%a %b %d %H:%M:%S %Z %Y" # Full format with timezone
# tzinfo=None
cdatetime = datetime.datetime(2010, 4, 27, 12, 0, 0, 0) # 1. Your example from log
cdatetime = datetime.datetime.now() # 2. Basic date creation (default: local time)
print(cdatetime.strftime(f)) # no timezone printed
# Tue Apr 27 12:00:00 2010
utctimestamp = cdatetime.astimezone(tz=datetime.timezone.utc) # 1. convert to UTC
utctimestamp = datetime.datetime.now(tz=datetime.timezone.utc) # 2. create in UTC
print(utctimestamp.strftime(f))
# Tue Apr 27 17:00:00 UTC 2010
localtimestamp = cdatetime.astimezone() # 1. convert to local [default]
localtimestamp = datetime.datetime.now().astimezone() # 2. create with local timezone
print(localtimestamp.strftime(f))
# Tue Apr 27 12:00:00 CDT 2010
The '%Z' parameter of datetime.strftime() prints the timezone acronym into the timestamp for humans to read.
For simple things, the following tzinfo implementation can be used, which queries the OS for time zone offsets:
import datetime
import time
class LocalTZ(datetime.tzinfo):
_unixEpochOrdinal = datetime.datetime.utcfromtimestamp(0).toordinal()
def dst(self, dt):
return datetime.timedelta(0)
def utcoffset(self, dt):
t = (dt.toordinal() - self._unixEpochOrdinal)*86400 + dt.hour*3600 + dt.minute*60 + dt.second + time.timezone
utc = datetime.datetime(*time.gmtime(t)[:6])
local = datetime.datetime(*time.localtime(t)[:6])
return local - utc
print datetime.datetime.now(LocalTZ())
print datetime.datetime(2010, 4, 27, 12, 0, 0, tzinfo=LocalTZ())
# If you're in the EU, the following datetimes are right on the DST change.
print datetime.datetime(2013, 3, 31, 0, 59, 59, tzinfo=LocalTZ())
print datetime.datetime(2013, 3, 31, 1, 0, 0, tzinfo=LocalTZ())
print datetime.datetime(2013, 3, 31, 1, 59, 59, tzinfo=LocalTZ())
# The following datetime is invalid, as the clock moves directly from
# 01:59:59 standard time to 03:00:00 daylight savings time.
print datetime.datetime(2013, 3, 31, 2, 0, 0, tzinfo=LocalTZ())
print datetime.datetime(2013, 10, 27, 0, 59, 59, tzinfo=LocalTZ())
print datetime.datetime(2013, 10, 27, 1, 0, 0, tzinfo=LocalTZ())
print datetime.datetime(2013, 10, 27, 1, 59, 59, tzinfo=LocalTZ())
# The following datetime is ambigous, as 02:00 can be either DST or standard
# time. (It is interpreted as standard time.)
print datetime.datetime(2013, 10, 27, 2, 0, 0, tzinfo=LocalTZ())
tzlocal from dateutil.
Code example follows. Last string suitable for use in filenames.
>>> from datetime import datetime
>>> from dateutil.tz import tzlocal
>>> str(datetime.now(tzlocal()))
'2015-04-01 11:19:47.980883-07:00'
>>> str(datetime.now(tzlocal())).replace(' ','-').replace(':','').replace('.','-')
'2015-04-01-111947-981879-0700'
>>>
First, note that the question presents an incorrect initialization of an aware datetime object:
>>> local_time=datetime.datetime(2010, 4, 27, 12, 0, 0, 0,
... tzinfo=pytz.timezone('Israel'))
creates an invalid instance. One can see the problem by computing the UTC offset of the resulting object:
>>> print(local_time.utcoffset())
2:21:00
(Note the result which is an odd fraction of an hour.)
To initialize an aware datetime properly using pytz one should use the localize() method as follows:
>>> local_time=pytz.timezone('Israel').localize(datetime.datetime(2010, 4, 27, 12))
>>> print(local_time.utcoffset())
3:00:00
Now, if you require a local pytz timezone as the new tzinfo, you should use the tzlocal package as others have explained, but if all you need is an instance with a correct local time zone offset and abbreviation then tarting with Python 3.3, you can call the astimezone() method with no arguments to convert an aware datetime instance to your local timezone:
>>> local_time.astimezone().strftime('%Y-%m-%d %H:%M %Z %z')
'2010-04-27 05:00 EDT -0400'
now_dt = datetime.datetime.now()
utc_now = datetime.datetime.utcnow()
now_ts, utc_ts = map(time.mktime, map(datetime.datetime.timetuple, (now_dt, utc_now)))
offset = int((now_ts - utc_ts) / 3600)
hope this will help you.

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