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Is there any proper method to convert ISO8601(with tzone) to milliseconds on python? [duplicate]

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How do I parse an ISO 8601-formatted date?
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I'm getting a datetime string in a format like "2009-05-28T16:15:00" (this is ISO 8601, I believe). One hackish option seems to be to parse the string using time.strptime and passing the first six elements of the tuple into the datetime constructor, like:
datetime.datetime(*time.strptime("2007-03-04T21:08:12", "%Y-%m-%dT%H:%M:%S")[:6])
I haven't been able to find a "cleaner" way of doing this. Is there one?

I prefer using the dateutil library for timezone handling and generally solid date parsing. If you were to get an ISO 8601 string like: 2010-05-08T23:41:54.000Z you'd have a fun time parsing that with strptime, especially if you didn't know up front whether or not the timezone was included. pyiso8601 has a couple of issues (check their tracker) that I ran into during my usage and it hasn't been updated in a few years. dateutil, by contrast, has been active and worked for me:
from dateutil import parser
yourdate = parser.parse(datestring)

Since Python 3.7 and no external libraries, you can use the fromisoformat function from the datetime module:
datetime.datetime.fromisoformat('2019-01-04T16:41:24+02:00')
Python 2 doesn't support the %z format specifier, so it's best to explicitly use Zulu time everywhere if possible:
datetime.datetime.strptime("2007-03-04T21:08:12Z", "%Y-%m-%dT%H:%M:%SZ")

Because ISO 8601 allows many variations of optional colons and dashes being present, basically CCYY-MM-DDThh:mm:ss[Z|(+|-)hh:mm]. If you want to use strptime, you need to strip out those variations first.
The goal is to generate a UTC datetime object.
If you just want a basic case that work for UTC with the Z suffix like 2016-06-29T19:36:29.3453Z:
datetime.datetime.strptime(timestamp.translate(None, ':-'), "%Y%m%dT%H%M%S.%fZ")
If you want to handle timezone offsets like 2016-06-29T19:36:29.3453-0400 or 2008-09-03T20:56:35.450686+05:00 use the following. These will convert all variations into something without variable delimiters like 20080903T205635.450686+0500 making it more consistent/easier to parse.
import re
# This regex removes all colons and all
# dashes EXCEPT for the dash indicating + or - utc offset for the timezone
conformed_timestamp = re.sub(r"[:]|([-](?!((\d{2}[:]\d{2})|(\d{4}))$))", '', timestamp)
datetime.datetime.strptime(conformed_timestamp, "%Y%m%dT%H%M%S.%f%z" )
If your system does not support the %z strptime directive (you see something like ValueError: 'z' is a bad directive in format '%Y%m%dT%H%M%S.%f%z') then you need to manually offset the time from Z (UTC). Note %z may not work on your system in Python versions < 3 as it depended on the C library support which varies across system/Python build type (i.e., Jython, Cython, etc.).
import re
import datetime
# This regex removes all colons and all
# dashes EXCEPT for the dash indicating + or - utc offset for the timezone
conformed_timestamp = re.sub(r"[:]|([-](?!((\d{2}[:]\d{2})|(\d{4}))$))", '', timestamp)
# Split on the offset to remove it. Use a capture group to keep the delimiter
split_timestamp = re.split(r"([+|-])",conformed_timestamp)
main_timestamp = split_timestamp[0]
if len(split_timestamp) == 3:
sign = split_timestamp[1]
offset = split_timestamp[2]
else:
sign = None
offset = None
# Generate the datetime object without the offset at UTC time
output_datetime = datetime.datetime.strptime(main_timestamp +"Z", "%Y%m%dT%H%M%S.%fZ" )
if offset:
# Create timedelta based on offset
offset_delta = datetime.timedelta(hours=int(sign+offset[:-2]), minutes=int(sign+offset[-2:]))
# Offset datetime with timedelta
output_datetime = output_datetime + offset_delta

Arrow looks promising for this:
>>> import arrow
>>> arrow.get('2014-11-13T14:53:18.694072+00:00').datetime
datetime.datetime(2014, 11, 13, 14, 53, 18, 694072, tzinfo=tzoffset(None, 0))
Arrow is a Python library that provides a sensible, intelligent way of creating, manipulating, formatting and converting dates and times. Arrow is simple, lightweight and heavily inspired by moment.js and requests.

You should keep an eye on the timezone information, as you might get into trouble when comparing non-tz-aware datetimes with tz-aware ones.
It's probably the best to always make them tz-aware (even if only as UTC), unless you really know why it wouldn't be of any use to do so.
#-----------------------------------------------
import datetime
import pytz
import dateutil.parser
#-----------------------------------------------
utc = pytz.utc
BERLIN = pytz.timezone('Europe/Berlin')
#-----------------------------------------------
def to_iso8601(when=None, tz=BERLIN):
if not when:
when = datetime.datetime.now(tz)
if not when.tzinfo:
when = tz.localize(when)
_when = when.strftime("%Y-%m-%dT%H:%M:%S.%f%z")
return _when[:-8] + _when[-5:] # Remove microseconds
#-----------------------------------------------
def from_iso8601(when=None, tz=BERLIN):
_when = dateutil.parser.parse(when)
if not _when.tzinfo:
_when = tz.localize(_when)
return _when
#-----------------------------------------------

I haven't tried it yet, but pyiso8601 promises to support this.

import datetime, time
def convert_enddate_to_seconds(self, ts):
"""Takes ISO 8601 format(string) and converts into epoch time."""
dt = datetime.datetime.strptime(ts[:-7],'%Y-%m-%dT%H:%M:%S.%f')+\
datetime.timedelta(hours=int(ts[-5:-3]),
minutes=int(ts[-2:]))*int(ts[-6:-5]+'1')
seconds = time.mktime(dt.timetuple()) + dt.microsecond/1000000.0
return seconds
This also includes the milliseconds and time zone.
If the time is '2012-09-30T15:31:50.262-08:00', this will convert into epoch time.
>>> import datetime, time
>>> ts = '2012-09-30T15:31:50.262-08:00'
>>> dt = datetime.datetime.strptime(ts[:-7],'%Y-%m-%dT%H:%M:%S.%f')+ datetime.timedelta(hours=int(ts[-5:-3]), minutes=int(ts[-2:]))*int(ts[-6:-5]+'1')
>>> seconds = time.mktime(dt.timetuple()) + dt.microsecond/1000000.0
>>> seconds
1348990310.26

Both ways:
Epoch to ISO time:
isoTime = time.strftime('%Y-%m-%dT%H:%M:%SZ', time.gmtime(epochTime))
ISO time to Epoch:
epochTime = time.mktime(time.strptime(isoTime, '%Y-%m-%dT%H:%M:%SZ'))

Isodate seems to have the most complete support.

aniso8601 should handle this. It also understands timezones, Python 2 and Python 3, and it has a reasonable coverage of the rest of ISO 8601, should you ever need it.
import aniso8601
aniso8601.parse_datetime('2007-03-04T21:08:12')

Here is a super simple way to do these kind of conversions.
No parsing, or extra libraries required.
It is clean, simple, and fast.
import datetime
import time
################################################
#
# Takes the time (in seconds),
# and returns a string of the time in ISO8601 format.
# Note: Timezone is UTC
#
################################################
def TimeToISO8601(seconds):
strKv = datetime.datetime.fromtimestamp(seconds).strftime('%Y-%m-%d')
strKv = strKv + "T"
strKv = strKv + datetime.datetime.fromtimestamp(seconds).strftime('%H:%M:%S')
strKv = strKv +"Z"
return strKv
################################################
#
# Takes a string of the time in ISO8601 format,
# and returns the time (in seconds).
# Note: Timezone is UTC
#
################################################
def ISO8601ToTime(strISOTime):
K1 = 0
K2 = 9999999999
K3 = 0
counter = 0
while counter < 95:
K3 = (K1 + K2) / 2
strK4 = TimeToISO8601(K3)
if strK4 < strISOTime:
K1 = K3
if strK4 > strISOTime:
K2 = K3
counter = counter + 1
return K3
################################################
#
# Takes a string of the time in ISO8601 (UTC) format,
# and returns a python DateTime object.
# Note: returned value is your local time zone.
#
################################################
def ISO8601ToDateTime(strISOTime):
return time.gmtime(ISO8601ToTime(strISOTime))
#To test:
Test = "2014-09-27T12:05:06.9876"
print ("The test value is: " + Test)
Ans = ISO8601ToTime(Test)
print ("The answer in seconds is: " + str(Ans))
print ("And a Python datetime object is: " + str(ISO8601ToDateTime(Test)))

What is the Python equivalent of Javascript's `Date.prototype.toISOString`?

In Javascript, Date.prototype.toISOString gives an ISO 8601 UTC datetime string:
new Date().toISOString()
// "2014-07-24T00:19:37.439Z"
Is there a Python function with behavior that matches Javascript's?
Attempts:
Python's datetime.datetime.isoformat is similar, but not quite the same:
datetime.datetime.now().isoformat()
// '2014-07-24T00:19:37.439728'
Using pytz I can at least make UTC explicit:
pytz.utc.localize(datetime.now()).isoformat())
// '2014-07-24T00:19:37.439728+00:00'

You can use this code:
import datetime
now = datetime.datetime.now()
iso_time = now.strftime("%Y-%m-%dT%H:%M:%SZ")

This did it for me, just using python's standard library:
from datetime import datetime, timezone
def isoformat_js(dt: datetime):
return (
dt.astimezone(timezone.utc)
.isoformat(timespec="milliseconds")
.replace("+00:00", "Z")
)
isoformat_js(datetime(2014, 7, 24, 0, 19, 37, 439000))
# => '2014-07-24T00:19:37.439Z'

I attempted to format the string to exactly how it is in the javascript output.
from datetime import datetime
def iso_format(dt):
try:
utc = dt + dt.utcoffset()
except TypeError as e:
utc = dt
isostring = datetime.strftime(utc, '%Y-%m-%dT%H:%M:%S.{0}Z')
return isostring.format(int(round(utc.microsecond/1000.0)))
print iso_format(datetime.now())
#"2014-07-24T00:19:37.439Z"

Using f-strings in Python 3.6+
from datetime import datetime
f'{datetime.now():%Y-%m-%dT%H:%M:%SZ}'

# Used dateutil package from https://pypi.org/project/python-dateutil/
import datetime
import dateutil.tz
def iso_format(dt):
try:
utc_dt = dt.astimezone(dateutil.tz.tzutc())
except ValueError:
utc_dt = dt
ms = "{:.3f}".format(utc_dt.microsecond / 1000000.0)[2:5]
return datetime.datetime.strftime(utc_dt, '%Y-%m-%dT%H:%M:%S.{0}Z'.format(ms))

Is there a Python function with behavior that matches Javascript's?
Not in the standard library, but you could build your own.

The issue is ISO 8601 date format itself allows for two things:
Use of either 'Z' or '+00:00' to represent UTC as used by javascript and python respectively
Number of digits in the decimal fraction of a second is not limited. So, python uses 6 (microsecond precision) and javascript uses 3 (millisecond precision)
So, both are correct and we need to handle the conversion with one or more of the tricks above. I use the following:
Python date object to javascript ISO format string:
pyDateObj = datetime.now() jsISOTimeStr = pyDateObj.astimezone(pytz.timezone("UTC")).isoformat()[:-9] + 'Z'
Javascript date object to python ISO format string:
In javascript:
const jsDateObj = new Date(); jsISOTimeStr = date.toISOString()
Later, in python:
pyDateObj = datetime.fromisoformat(jsISOTimeStr [:-1]+'000+00:00')

you may also use:
import datetime
nowinIsoFromat = datetime.datetime.now().isoformat("T", "milliseconds") + 'Z'

How to construct a timedelta object from a simple string

I'm writing a function that needs to parse string to a timedelta. The user must enter something like "32m" or "2h32m", or even "4:13" or "5hr34m56s"... Is there a library or something that has this sort of thing already implemented?

To me the most elegant solution, without having to resort to external libraries such as dateutil or manually parsing the input, is to use datetime's powerful strptime string parsing method.
from datetime import datetime, timedelta
# we specify the input and the format...
t = datetime.strptime("05:20:25","%H:%M:%S")
# ...and use datetime's hour, min and sec properties to build a timedelta
delta = timedelta(hours=t.hour, minutes=t.minute, seconds=t.second)
After this you can use your timedelta object as normally, convert it to seconds to make sure we did the correct thing etc.
print(delta)
assert(5*60*60+20*60+25 == delta.total_seconds())

I had a bit of time on my hands yesterday, so I developed #virhilo's answer into a Python module, adding a few more time expression formats, including all those requested by #priestc.
Source code is on github (MIT License) for anybody that wants it. It's also on PyPI:
pip install pytimeparse
Returns the time as a number of seconds:
>>> from pytimeparse.timeparse import timeparse
>>> timeparse('32m')
1920
>>> timeparse('2h32m')
9120
>>> timeparse('4:13')
253
>>> timeparse('5hr34m56s')
20096
>>> timeparse('1.2 minutes')
72

For the first format (5hr34m56s), you should parse using regular expressions
Here is re-based solution:
import re
from datetime import timedelta
regex = re.compile(r'((?P<hours>\d+?)hr)?((?P<minutes>\d+?)m)?((?P<seconds>\d+?)s)?')
def parse_time(time_str):
parts = regex.match(time_str)
if not parts:
return
parts = parts.groupdict()
time_params = {}
for name, param in parts.items():
if param:
time_params[name] = int(param)
return timedelta(**time_params)
>>> from parse_time import parse_time
>>> parse_time('12hr')
datetime.timedelta(0, 43200)
>>> parse_time('12hr5m10s')
datetime.timedelta(0, 43510)
>>> parse_time('12hr10s')
datetime.timedelta(0, 43210)
>>> parse_time('10s')
datetime.timedelta(0, 10)
>>>

I wanted to input just a time and then add it to various dates so this worked for me:
from datetime import datetime as dtt
time_only = dtt.strptime('15:30', "%H:%M") - dtt.strptime("00:00", "%H:%M")

I've modified virhilo's nice answer with a few upgrades:
added a assertion that the string is a valid time string
replace the "hr" hour-indicator with "h"
allow for a "d" - days indicator
allow non-integer times (e.g. 3m0.25s is 3 minutes, 0.25 seconds)
.
import re
from datetime import timedelta
regex = re.compile(r'^((?P<days>[\.\d]+?)d)?((?P<hours>[\.\d]+?)h)?((?P<minutes>[\.\d]+?)m)?((?P<seconds>[\.\d]+?)s)?$')
def parse_time(time_str):
"""
Parse a time string e.g. (2h13m) into a timedelta object.
Modified from virhilo's answer at https://stackoverflow.com/a/4628148/851699
:param time_str: A string identifying a duration. (eg. 2h13m)
:return datetime.timedelta: A datetime.timedelta object
"""
parts = regex.match(time_str)
assert parts is not None, "Could not parse any time information from '{}'. Examples of valid strings: '8h', '2d8h5m20s', '2m4s'".format(time_str)
time_params = {name: float(param) for name, param in parts.groupdict().items() if param}
return timedelta(**time_params)

If Pandas is already in your dependencies, it does this pretty well:
>>> import pandas as pd
>>> pd.Timedelta('5hr34m56s')
Timedelta('0 days 05:34:56')
>>> pd.Timedelta('2h32m')
Timedelta('0 days 02:32:00')
>>> pd.Timedelta('5hr34m56s')
Timedelta('0 days 05:34:56')
>>> # It is pretty forgiving:
>>> pd.Timedelta('2 days 24:30:00 10 sec')
Timedelta('3 days 00:30:10')
To convert to datetime.timedelta if you prefer that type:
>>> pd.Timedelta('1 days').to_pytimedelta()
datetime.timedelta(1)
Unfortunately this does not work though:
>>> pd.Timedelta('4:13')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "pandas\_libs\tslibs\timedeltas.pyx", line 1217, in
pandas._libs.tslibs.timedeltas.Timedelta.__new__
File "pandas\_libs\tslibs\timedeltas.pyx", line 454, in
pandas._libs.tslibs.timedeltas.parse_timedelta_string
ValueError: expected hh:mm:ss format
Pandas actually has pretty extensive date and time tools even though that is not its main purpose.
To install Pandas:
# If you use pip
pip install pandas
# If you use conda
conda install pandas

Django comes with the utility function parse_duration(). From the documentation:
Parses a string and returns a datetime.timedelta.
Expects data in the format "DD HH:MM:SS.uuuuuu" or as specified by ISO 8601 (e.g. P4DT1H15M20S which is equivalent to 4 1:15:20) or PostgreSQL's day-time interval format (e.g. 3 days 04:05:06).

if you want to use : as separator, I use this function:
import re
from datetime import timedelta
def timedelta_parse(value):
"""
convert input string to timedelta
"""
value = re.sub(r"[^0-9:.]", "", value)
if not value:
return
return timedelta(**{key:float(val)
for val, key in zip(value.split(":")[::-1],
("seconds", "minutes", "hours", "days"))
})
Examples:
In [4]: timedelta_parse("1:0:0:1")
Out[4]: datetime.timedelta(days=1, seconds=1)
In [5]: timedelta_parse("123.5")
Out[5]: datetime.timedelta(seconds=123, microseconds=500000)
In [6]: timedelta_parse("1:6:34:9.983")
Out[6]: datetime.timedelta(days=1, seconds=23649, microseconds=983000)
In [8]: timedelta_parse("23:45:00")
Out[8]: datetime.timedelta(seconds=85500)

Use isodate library to parse ISO 8601 duration string. For example:
isodate.parse_duration('PT1H5M26S')
Also see Is there an easy way to convert ISO 8601 duration to timedelta?

If you use Python 3 then here's updated version for Hari Shankar's solution, which I used:
from datetime import timedelta
import re
regex = re.compile(r'(?P<hours>\d+?)/'
r'(?P<minutes>\d+?)/'
r'(?P<seconds>\d+?)$')
def parse_time(time_str):
parts = regex.match(time_str)
if not parts:
return
parts = parts.groupdict()
print(parts)
time_params = {}
for name, param in parts.items():
if param:
time_params[name] = int(param)
return timedelta(**time_params)

Consider trying tempora.parse_timedelta.
$ pip-run 'tempora>=4.1.1'
Collecting tempora>=4.1.1
Downloading tempora-4.1.1-py3-none-any.whl (15 kB)
Collecting jaraco.functools>=1.20
Using cached jaraco.functools-3.3.0-py3-none-any.whl (6.8 kB)
Collecting pytz
Using cached pytz-2021.1-py2.py3-none-any.whl (510 kB)
Collecting more-itertools
Using cached more_itertools-8.8.0-py3-none-any.whl (48 kB)
Installing collected packages: more-itertools, pytz, jaraco.functools, tempora
Successfully installed jaraco.functools-3.3.0 more-itertools-8.8.0 pytz-2021.1 tempora-4.1.1
Python 3.9.2 (v3.9.2:1a79785e3e, Feb 19 2021, 09:06:10)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from tempora import parse_timedelta
>>> parse_timedelta("32m")
datetime.timedelta(seconds=1920)
>>> parse_timedelta("2h32m")
datetime.timedelta(seconds=9120)
>>> parse_timedelta("4:13")
datetime.timedelta(seconds=15180)
>>> parse_timedelta("5hr34m56s")
datetime.timedelta(seconds=20096)

string to datetime with fractional seconds, on Google App Engine

I need to convert a string to a datetime object, along with the fractional seconds. I'm running into various problems.
Normally, i would do:
>>> datetime.datetime.strptime(val, "%Y-%m-%dT%H:%M:%S.%f")
But errors and old docs showed me that python2.5's strptime does not have %f...
Investigating further, it seems that the App Engine's data store does not like fractional seconds. Upon editing a datastore entity, trying to add .5 to the datetime field gave me the following error:
ValueError: unconverted data remains: .5
I doubt that fractional seconds are not supported... so this is just on the datastore viewer, right?
Has anyone circumvented this issue? I want to use the native datetime objects... I rather not store UNIX timestamps...
Thanks!
EDIT: Thanks to Jacob Oscarson for the .replace(...) tip!
One thing to keep in mind is to check the length of nofrag before feeding it in. Different sources use different precision for seconds.
Here's a quick function for those looking for something similar:
def strptime(val):
if '.' not in val:
return datetime.datetime.strptime(val, "%Y-%m-%dT%H:%M:%S")
nofrag, frag = val.split(".")
date = datetime.datetime.strptime(nofrag, "%Y-%m-%dT%H:%M:%S")
frag = frag[:6] # truncate to microseconds
frag += (6 - len(frag)) * '0' # add 0s
return date.replace(microsecond=int(frag))

Parsing
Without the %f format support for datetime.datetime.strptime() you can still sufficiently easy enter it into a datetime.datetime object (randomly picking a value for your val here) using datetime.datetime.replace()), tested on 2.5.5:
>>> val = '2010-08-06T10:00:14.143896'
>>> nofrag, frag = val.split('.')
>>> nofrag_dt = datetime.datetime.strptime(nofrag, "%Y-%m-%dT%H:%M:%S")
>>> dt = nofrag_dt.replace(microsecond=int(frag))
>>> dt
datetime.datetime(2010, 8, 6, 10, 0, 14, 143896)
Now you have your datetime.datetime object.
Storing
Reading further into http://code.google.com/appengine/docs/python/datastore/typesandpropertyclasses.html#datetime
I can see no mentioning that fractions isn't supported, so yes, it's probably only the datastore viewer. The docs points directly to Python 2.5.2's module docs for datetime, and it does support fractions, just not the %f parsing directive for strptime. Querying for fractions might be trickier, though..

All ancient history by now, but in these modern times you can also conveniently use dateutil
from dateutil import parser as DUp
funky_time_str = "1/1/2011 12:51:00.0123 AM"
foo = DUp.parse(funky_time_str)
print foo.timetuple()
# time.struct_time(tm_year=2011, tm_mon=1, tm_mday=1, tm_hour=0, tm_min=51, tm_sec=0, tm_wday=5, tm_yday=1, tm_isdst=-1)
print foo.microsecond
# 12300
print foo
# 2011-01-01 00:51:00.012300
dateutil supports a surprising variety of possible input formats, which it parses without pattern strings.

Convert an RFC 3339 time to a standard Python timestamp

Is there an easy way to convert an RFC 3339 time into a regular Python timestamp?
I've got a script which is reading an ATOM feed and I'd like to be able to compare the timestamp of an item in the ATOM feed to the modification time of a file.
I notice from the ATOM spec, that ATOM dates include a time zone offset (Z<a number>) but, in my case, there's nothing after the Z so I guess we can assume GMT.
I suppose I could parse the time with a regex of some sort but I was hoping Python had a built-in way of doing it that I just haven't been able to find.

You don't include an example, but if you don't have a Z-offset or timezone, and assuming you don't want durations but just the basic time, then maybe this will suit you:
import datetime as dt
>>> dt.datetime.strptime('1985-04-12T23:20:50.52', '%Y-%m-%dT%H:%M:%S.%f')
datetime.datetime(1985, 4, 12, 23, 20, 50, 520000)
The strptime() function was added to the datetime module in Python 2.5 so some people don't yet know it's there.
Edit: The time.strptime() function has existed for a while though, and works about the same to give you a struct_time value:
>>> ts = time.strptime('1985-04-12T23:20:50.52', '%Y-%m-%dT%H:%M:%S.%f')
>>> ts
time.struct_time(tm_year=1985, tm_mon=4, tm_mday=12, tm_hour=23, tm_min=20, tm_sec=50, tm_wday=4, tm_yday=102, tm_isdst=-1)
>>> time.mktime(ts)
482210450.0

I struggled with RFC3339 datetime format a lot, but I found a suitable solution to convert date_string <=> datetime_object in both directions.
You need two different external modules, because one of them is is only able to do the conversion in one direction (unfortunately):
first install:
sudo pip install rfc3339
sudo pip install iso8601
then include:
import datetime # for general datetime object handling
import rfc3339 # for date object -> date string
import iso8601 # for date string -> date object
For not needing to remember which module is for which direction, I wrote two simple helper functions:
def get_date_object(date_string):
return iso8601.parse_date(date_string)
def get_date_string(date_object):
return rfc3339.rfc3339(date_object)
which inside your code you can easily use like this:
input_string = '1989-01-01T00:18:07-05:00'
test_date = get_date_object(input_string)
# >>> datetime.datetime(1989, 1, 1, 0, 18, 7, tzinfo=<FixedOffset '-05:00' datetime.timedelta(-1, 68400)>)
test_string = get_date_string(test_date)
# >>> '1989-01-01T00:18:07-05:00'
test_string is input_string # >>> True
Heureka! Now you can easily (haha) use your date strings and date strings in a useable format.

No builtin, afaik.
feed.date.rfc3339
This is a Python library module with functions for converting timestamp strings in RFC 3339 format to Python time float values, and vice versa. RFC 3339 is the timestamp format used by the Atom feed syndication format.
It is BSD-licensed.
http://home.blarg.net/~steveha/pyfeed.html
(Edited so it's clear I didn't write it. :-)

The new datetime.fromisoformat(date_string) method which was added in Python 3.7 will parse most RFC 3339 timestamps, including those with time zone offsets. It's not a full implementation, so be sure to test your use case.
>>> from datetime import datetime
>>> datetime.fromisoformat('2011-11-04')
datetime.datetime(2011, 11, 4, 0, 0)
>>> datetime.fromisoformat('2011-11-04T00:05:23')
datetime.datetime(2011, 11, 4, 0, 5, 23)
>>> datetime.fromisoformat('2011-11-04 00:05:23.283')
datetime.datetime(2011, 11, 4, 0, 5, 23, 283000)
>>> datetime.fromisoformat('2011-11-04 00:05:23.283+00:00')
datetime.datetime(2011, 11, 4, 0, 5, 23, 283000, tzinfo=datetime.timezone.utc)
>>> datetime.fromisoformat('2011-11-04T00:05:23+04:00')
datetime.datetime(2011, 11, 4, 0, 5, 23,
tzinfo=datetime.timezone(datetime.timedelta(seconds=14400)))

If you're using Django, you could use Django's function parse_datetime:
>>> from django.utils.dateparse import parse_datetime
>>> parse_datetime("2016-07-19T07:30:36+05:00")
datetime.datetime(2016, 7, 19, 7, 30, 36, tzinfo=<django.utils.timezone.FixedOffset object at 0x101c0c1d0>)

http://pypi.python.org/pypi/iso8601/ seems to be able to parse iso 8601, which RFC 3339 is a subset of, maybe this could be useful, but again, not built-in.

The simplest solution for me has been dateutil python standart library.
from dateutil.parser import parse
dt = "2020-11-23T11:08:23.022277705Z"
print(parse(dt))
Output:
2020-11-23 11:08:23.022277+00:00
If you don't need the timezone element, just simply set timezone info to None
print(parse(t).replace(tzinfo=None))
The output is a nice and clean datetime object:
2020-11-23 11:08:23.022277

http://bugs.python.org/issue15873 (duplicate of http://bugs.python.org/issue5207 )
Looks like there isn't a built-in as of yet.

feedparser.py provides robust/extensible way to parse various date formats that may be encountered in real-world atom/rss feeds:
>>> from feedparser import _parse_date as parse_date
>>> parse_date('1985-04-12T23:20:50.52Z')
time.struct_time(tm_year=1985, tm_mon=4, tm_mday=12, tm_hour=23, tm_min=20,
tm_sec=50, tm_wday=4, tm_yday=102, tm_isdst=1)

try this, it works fine for me
datetime_obj = datetime.strptime("2014-01-01T00:00:00Z", '%Y-%m-%dT%H:%M:%SZ')
or
datetime_obj = datetime.strptime("Mon, 01 Jun 2015 16:41:40 GMT", '%a, %d %b %Y %H:%M:%S GMT')

Came across the awesome dateutil.parser module in another question, and tried it on my RFC3339 problem, and it appears to handle everything I throw at it with more sanity that any of the other responses in this question.

Using Python 3, you can use RegEx to break the RFC 3339 timestamp into its components.
Then, directly create the datetime object, no additional modules needed:
import re
import datetime
def parse_rfc3339(dt):
broken = re.search(r'([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})(\.([0-9]+))?(Z|([+-][0-9]{2}):([0-9]{2}))', dt)
return(datetime.datetime(
year = int(broken.group(1)),
month = int(broken.group(2)),
day = int(broken.group(3)),
hour = int(broken.group(4)),
minute = int(broken.group(5)),
second = int(broken.group(6)),
microsecond = int(broken.group(8) or "0"),
tzinfo = datetime.timezone(datetime.timedelta(
hours = int(broken.group(10) or "0"),
minutes = int(broken.group(11) or "0")))))
This example theads missing timezones or microseconds as "0" but might need additional error checking.
Cheers, Alex

You could use a Google API Core package. They have a really straightforward Datetime to RFC 3339 conversion function. You can find more info in their docs.
Its usage is as simple as:
from google.api_core.datetime_helpers import to_rfc3339
rfc3339_str = to_rfc3339(datetime.now())
They even have a function that works the other way around from_rfc3339 and from_rfc3339_nanos.

rfc3339 library: http://henry.precheur.org/python/rfc3339

I have been doing a deep dive in dateimes and RFC3339 and recently come across the arrow library and have just used and solved my problem:
import arrow
date_string = "2015-11-24 00:00:00+00:00"
my_datetime = arrow.get(date_string).datetime