I have the following string:
mytime = "2009-03-08T00:27:31.807Z"
How do I convert it to epoch in python?
I tried:
import time
p = '%Y-%m-%dT%H:%M:%S'
int(time.mktime(time.strptime(s, p)))
But it does not work with the 31.807Z.
7 Answers
There are two parts:
- Convert the time string into a broken-down time. See How to parse ISO formatted date in python?
- Convert the UTC time to "seconds since the Epoch" (POSIX timestamp).
#!/usr/bin/env python
from datetime import datetime
utc_time = datetime.strptime("2009-03-08T00:27:31.807Z", "%Y-%m-%dT%H:%M:%S.%fZ")
epoch_time = (utc_time - datetime(1970, 1, 1)).total_seconds()
# -> 1236472051.807
If you are sure that you want to ignore fractions of a second and to get an integer result:
#!/usr/bin/env python
import time
from calendar import timegm
utc_time = time.strptime("2009-03-08T00:27:31.807Z", "%Y-%m-%dT%H:%M:%S.%fZ")
epoch_time = timegm(utc_time)
# -> 1236472051
To support timestamps that correspond to a leap second such as Wed July 1 2:59:60 MSK 2015, you could use a combination of time.strptime() and datetime (if you care about leap seconds you should take into account the microseconds too).
2 Comments
Joran Beasley
what if you get "2009-03-08T00:27:31.807A" or any offset from zulu time? but +1 for locale aware time conversion :)
jfs
@JoranBeasley In practice, rfc 3339 works unless you have some special requirements.
Z is the only allowed letter tools.ietf.org/html/rfc3339#section-5.6dateutil has recently been added back to python packages, it's an easy one liner that handles formatting on its own.
from dateutil import parser
strtime = '2009-03-08T00:27:31.807Z'
epoch = parser.parse(strtime).timestamp()
1 Comment
Thavas Antonio
Only answers with no context and extra text are not the best. You are basically asking the OP to copy and paste your answer without knowing what the code does. Please provide an explanation. Thank You!
You are missing .%fZ from your format string.
p = '%Y-%m-%dT%H:%M:%S.%fZ'
The correct way to convert to epoch is to use datetime:
from datetime import datetime
p = '%Y-%m-%dT%H:%M:%S.%fZ'
mytime = "2009-03-08T00:27:31.807Z"
epoch = datetime(1970, 1, 1)
print((datetime.strptime(mytime, p) - epoch).total_seconds())
Or call int if you want to ignore fractions.
answered May 26, 2015 at 20:41
Padraic Cunningham
181k30 gold badges264 silver badges327 bronze badges
8 Comments
Padraic Cunningham
@JoranBeasley. In my infinite wisdom I predicted it would always end in
Z, I suppose you could always ignore Z and rstrip("Z")jfs
don't use
time.mktime() on UTC time!Joran Beasley
here are the possible terminal characters en.wikipedia.org/wiki/List_of_military_time_zones .... its usually Z for most things but that letter has meaning that this discards :/ still solid answer of coarse :)
Padraic Cunningham
@J.F.Sebastian, yes, I read the post when you commented on joran's answer.
jfs
I've downvoted and left the comment about
mktime(). "OP uses broken code in the question" is not a valid excuse for putting it in your answer. Personally, I add something like #XXX WRONG, DON'T USE at the top of a code fragment if I have to include the broken code. It is not enough to put a valid answer somewhere at the bottom. |
dateutil is the only library i have found that correctly deals with the timezone offset identitifier (Z)
pip install python-dateutil
then
from dateutil.parser import parse as date_parse
print date_parse("2009-03-08T00:27:31.807Z")
#get timestamp
import calendar
dt = date_parse("2009-03-08T00:27:31.807Z")
timestamp1 = calendar.timegm(dt.timetuple())
5 Comments
Padraic Cunningham
probably a more robust solution.
jfs
@PadraicCunningham: it is less robust if you want to reject timestamps that use a wrong format.
dateutil may accept too much.jfs
it is an overkill to use
dateutil for that. You can parse the time string using only stdlib in both Python 2 and 3. timegm() is ok if you don't care about fractions of a second.Joran Beasley
not if you dont want to lose the information imparted by the terminal letter en.wikipedia.org/wiki/List_of_military_time_zones
Code:
import datetime
epoch = datetime.datetime(1970, 1, 1)
mytime = "2009-03-08T00:27:31.807Z"
myformat = "%Y-%m-%dT%H:%M:%S.%fZ"
mydt = datetime.datetime.strptime(mytime, myformat)
val = (mydt - epoch).total_seconds()
print(val)
> 1236472051.81
repr(val)
> '1236472051.807'
Notes:
- When using
time.strptime(), the returnedtime.struct_timedoes not support sub-second precision. - The
%fformat is for microseconds. When parsing it need not be the full 6 digits.
Comments
This code works in Python 3.6 to convert a datetime string to epoch in UTC or local timezone.
from datetime import datetime, timedelta
from dateutil.tz import tzutc, tzlocal
mydate = '2020-09-25'
mytime = '06:00:00'
epoch1970 = datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
myepochutc = int((datetime.strptime(mydate + ' ' + mytime, "%Y-%m-%d %H:%M:%S").replace(tzinfo=tzutc()) - epoch1970).total_seconds()*1000)
myepochlocal = int((datetime.strptime(mydate + ' ' + mytime, "%Y-%m-%d %H:%M:%S").replace(tzinfo=tzlocal()) - epoch1970).total_seconds()*1000)
#epoch will be in milliseconds
print(myepochutc) #if mydate/mytime was in utc
print(myepochlocal) #if mydate/mytime was in local timezone
Comments
Python 3.7+ The string format in question can be parsed by strptime:
from datetime import datetime
datetime.strptime("2009-03-08T00:27:31.807Z", '%Y-%m-%dT%H:%M:%S.%f%z')
>>> datetime.datetime(2009, 3, 8, 0, 27, 31, 807000, tzinfo=datetime.timezone.utc)
Another option using the built-in datetime.fromisoformat(): As mentioned in this thread linked by @jfs, fromisoformat() doesn't parse the 'Z' character to UTC although this is part of the RFC3339 definitions. A little work-around can make it work - some will consider this nasty but it's efficient after all.
from datetime import datetime
mytime = "2009-03-08T00:27:31.807Z"
datetime.fromisoformat(mytime.replace("Z", "+00:00")).timestamp()
>>> 1236472051.807
1 Comment
FObersteiner
.807Z? %S shows as a decimal number