python convert date and time into linux timestmap - python

i have timestamps in the following format:
2011 February 2nd 13h 27min 21s
110202 132721
I want to convert 110202 132721 into the corresponding linux timestamp: 1296682041
Is there any quick efficient way to achieve this?

Something like
>>> s = "110202 132721"
>>> print time.mktime(time.strptime(s, "%y%m%d %H%M%S"))
1296653241.0
This interprets the time as a local time (your current time zone).

To create a Unix timestamp, use the time.mktime(t) function. It takes a time.struct_time object.
The objects definition can be viewed here. So you just have to parse the date and the time and put it into the object before handing it over to the mktime() function

Without your timezone information, this is not the 'corresponding' unix timestamp.
After a few attempts I have guessed you could be located in the Pacific coast of USA, so you have to define it explicitely in your script:
from datetime import datetime
import pytz
import calendar
a = "110202 132721"
yourTZ = 'America/Los_Angeles'
calendar.timegm(pytz.timezone(yourTZ).localize(datetime.strptime(a, '%y%m%d %H%M%S')).utctimetuple())
# returns 1296682041

Related

Finding local time zone using Python

I want to find my local time zone and then return the time zone name (cet, est etc.) using Python and my location so that I can just find it without entering any additional information except for the location of my pc (which I want to find using GPS and not manually adding it)
import say
import datetime
def timezone():
timezone = datetime.datetime.now()
timezonename = timezone.strftime("%Z")
timezoneoffset = timezone.strftime("%z")
say.praten(f"the timezone is {timezonename} which is {timezoneoffset} off UTC")
I used this but this doesn't return anything with the datetime import
the say command is from a different file for text to speech
everyone is revering me to this post : Get system local timezone in python
but I tried this and I got the full name of the time zone (Europe Berlin) but I want the 3 letter name (cet in my case)
You can use the time module to get your local timezone:
import time
print(time.tzname)
This gets you a tuple like ('CET', 'CEST').
borrowing from this answer to the linked Q&A, you can also do
from datetime import datetime
dt_local = datetime.now().astimezone()
print(dt_local.isoformat(timespec="seconds"))
print(dt_local.strftime("%Z"))
# on my machine:
# 2022-11-09T18:50:13+01:00
# CET
The important part is to make the datetime object aware of the local time zone (setting of your machine) by calling .astimezone().

How do I get the full timezone name from a Datetime without importing Time?

I'm trying to display my full time zone along with my current local time.
print "Your current time is {0} {1} ".format(datetime.datetime.now().time(), time.tzname[0])
And the result would look something like:
Your current time is 08:35:45.328000 Pacific Standard Time
The problem is I have to import the Time library (sorry if I call it wrong, I'm coming from C#) along with the Datetime library.
import datetime
import time
I've looked into the naive and aware states of time, but still can't seem to get the desired result.
Is there a way to get the full timezone name (i.e.: Pacific Standard Time) from Datetime without having to import Time?
The example for writing your own local timezone tzinfo class uses (scroll down one page from here) pulls the tzname from time.tzname, so Python doesn't have a better built-in solution to suggest.
You could copy that example LocalTimezone implementation, which would allow the use of the %Z format code for strftime on an aware datetime instance using the LocalTimezone, but that's the best you can do with the built-ins. On a naive datetime the tzname is the empty string, so you need an aware datetime for this to work.

How should I serialize a dateutil.tz.tzlocal object?

I want to capture a timestamp and the current timezone and serialize it into a file (in JSON or YAML, but that's not really my question) for later retrieval on a different computer.
The timestamp is easy, I'll just use time.time().
For getting the current timezone, I read another SO question and it seems appropriate to use dateutil.tz.tzlocal
to get the current timezone.
Now I just need to figure out how to serialize it. The name is easy, that's just a string, but the offset seems to be weird; I was expecting just a number:
import time
import datetime
import dateutil
now = datetime.datetime.utcfromtimestamp(time.time())
tzlocal = dateutil.tz.tzlocal()
print tzlocal.tzname(now)
print tzlocal.utcoffset(now)
but this prints
US Mountain Standard Time
-1 day, 17:00:00
and the result of utcoffset appears to be an object. How do I just get the number?
Oh, never mind, tzlocal.utcoffset(now) returns a datetime.timedelta and I can just call total_seconds():
import time
import datetime
import dateutil
import json
now = datetime.datetime.utcfromtimestamp(time.time())
tzlocal = dateutil.tz.tzlocal()
info_str = json.dumps(dict(name=tzlocal.tzname(now),
offset=tzlocal.utcoffset(now).total_seconds()))
print info_str
which prints (on my PC)
{"name": "US Mountain Standard Time", "offset": -25200.0}
I'm not sure what your application is but as a default I recommend serializing to ISO 8601 timestamps with a time zone offset. Even better, convert to UTC first... this makes things easier for humans who happen to browse the serialized data, because they don't have to do the date math in their head.
There may be performance reasons for sticking with numeric timestamps, but I'd want proof this was a bottleneck in my application before giving up the human-readable bonus of ISO timestamps.

How do I get the current time and date of the operating system

How do I get the current time and date of the operating system (the one in the clock). I tried to use datetime.now(). But it returns different value.
As suggested by mcalex I've rechecked the time and date setting and this has always been like this:
Use time.localtime().
From https://docs.python.org/2/library/time.html#time.localtime
Like gmtime() but converts to local time. If secs is not provided or
None, the current time as returned by time() is used. The dst flag is
set to 1 when DST applies to the given time.
You can use the Python time module for various time-related functions. It appears you are requesting the following format:
Day Month Hour:Min:Sec Year
If so, you can use the following:
>>> import time
>>> time.asctime(time.localtime())
'Mon Jun 30 22:19:34 2014'
To convert to a specific format, you can use the following function:
time.strftime(format[, t])
This converts a struct_time object tm representing a time as returned by gmtime() or localtime() to a string. See the following link for more info on the format codes:
https://docs.python.org/2/library/time.html#time.localtime
Source: Beazley, D. M., "Python Essential Reference", 4th. Ed.

Elegant way to adjust date timezones in Python

I'm based in the UK, and grappling with summer time BST and timezones.
Here's my code:
TIME_OFFSET = 1 # 0 for GMT, 1 for BST
def RFC3339_to_localHHMM(input):
# Take an XML date (2013-04-08T22:35:00Z)
# return e.g. 08/04 23:35
return (datetime.datetime.strptime(input, '%Y-%m-%dT%H:%M:%SZ') +
datetime.timedelta(hours=TIME_OFFSET)).strftime('%d/%m %H:%M')
Setting a variable like this feels very wrong, but I can't find any elegant way to achieve the above without hideous amounts of code. Am I missing something, and is there no way to (for example) read the system timezone?
To convert UTC to given timezone:
from datetime import datetime
import pytz
local_tz = pytz.timezone("Europe/London") # time zone name from Olson database
def utc_to_local(utc_dt):
return utc_dt.replace(tzinfo=pytz.utc).astimezone(local_tz)
rfc3339s = "2013-04-08T22:35:00Z"
utc_dt = datetime.strptime(rfc3339s, '%Y-%m-%dT%H:%M:%SZ')
local_dt = utc_to_local(utc_dt)
print(local_dt.strftime('%d/%m %H:%M')) # -> 08/04 23:35
See also How to convert a python utc datetime to a local datetime using only python standard library?.
You seem to be asking a few separate questions here.
First, if you only care about your own machine's current local timezone, you don't need to know what it is. Just use the local-to-UTC functions. There are a few holes in the API, but even if you can't find the function you need, you can always just get from local to UTC or vice-versa by going through the POSIX timestamp and the fromtimestamp and utcfromtimestamp methods.
If you want to be able to deal with any timezone, see the top of the docs for the difference between aware and naive objects, but basically: an aware object is one that knows its timezone. So, that's what you need. The problem is that, as the docs say:
Note that no concrete tzinfo classes are supplied by the datetime module. Supporting timezones at whatever level of detail is required is up to the application.
The easiest way to support timezones is to install and use the third-party library pytz.
Meanwhile, as strftime() and strptime() Behavior sort-of explains, strptime always returns a naive object. You then have to call replace and/or astimezone (depending on whether the string was a UTC time or a local time) to get an aware object imbued with the right timezone.
But, even with all this, you still need to know what local timezone you're in, which means you still need a constant. In other words:
TIMEZONE = pytz.timezone('Europe/London')
def RFC3339_to_localHHMM(input):
# Take an XML date (2013-04-08T22:35:00Z)
# return e.g. 08/04 23:35
utc_naive = datetime.datetime.strptime(input, '%Y-%m-%dT%H:%M:%SZ')
utc = utc_naive.replace(pytz.utc)
bst = utc.astimezone(TIMEZONE)
return bst.strftime('%d/%m %H:%M')
So, how do you get the OS to give you the local timezone? Well, that's different for different platforms, and Python has nothing built in to help. But there are a few different third-party libraries that do, such as dateutil. For example:
def RFC3339_to_localHHMM(input):
# Take an XML date (2013-04-08T22:35:00Z)
# return e.g. 08/04 23:35
utc = datetime.datetime.strptime(input, '%Y-%m-%dT%H:%M:%SZ')
bst = utc.astimezone(dateutil.tz.tzlocal())
return bst.strftime('%d/%m %H:%M')
But now we've come full circle. If all you wanted was the local timezone, you didn't really need the timezone at all (at least for your simple use case). So, this is only necessary if you need to support any timezone, and also want to be able to, e.g., default to your local timezone (without having to write two copies of all of your code for the aware and naive cases).
(Also, if you're going to use dateutil in the first place, you might want to use it for more than just getting the timezone—it can basically replacing everything you're doing with both datetime and pytz.)
Of course there are other options besides these libraries—search PyPI, Google, and/or the ActiveState recipes.
If you want to convert a UTC input into a local time, regardless of which timezone you're in, try this:
def utctolocal(input):
if time.localtime()[-1] == 1: st=3600
else: st=0
return time.localtime(time.time()-time.mktime(time.gmtime())+time.mktime(time.localtime(time.mktime(time.strptime(input, '%Y-%m-%dT%H:%M:%SZ'))))+st)
Quite long code, but what it does is it simply adds the difference between time.gmtime() and time.localtime() to the time tuple created from the input.
Here's a function I use to do what I think you want. This assumes that the input is really a gmt, or more precisely, a utc datetime object:
def utc_to_local(utc_dt):
'''Converts a utc datetime obj to local datetime obj.'''
t = utc_dt.timetuple()
secs = calendar.timegm(t)
loc = time.localtime(secs)
return datetime.datetime.fromtimestamp(time.mktime(loc))
Like you said, this relies on the system time zone, which may give you shaky results, as some of the comments have pointed out. It has worked perfectly for me on Windows, however.
A simple function to check if a UCT corresponds to BST in London or GMT (for setting TIME_OFFSET above)
import datetime
def is_BST(input_date):
if input_date.month in range(4,9):
return True
if input_date.month in [11,12,1,2]:
return False
# Find start and end dates for current year
current_year = input_date.year
for day in range(25,32):
if datetime.datetime(current_year,3,day).weekday()==6:
BST_start = datetime.datetime(current_year,3,day,1)
if datetime.datetime(current_year,10,day).weekday()==6:
BST_end = datetime.datetime(current_year,10,day,1)
if (input_date > BST_start) and (input_date < BST_end):
return True
return False

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