I get following response from an API:
/Date(1503964800000+0000)/
It is a string object. How do I convert it in to something like
2017-08-11T00:00:00
You can use datetime.datetime.fromtimestamp]1 in combination with strftime:
import datetime
print(
datetime.datetime.fromtimestamp(int("1502440590")).strftime("%Y-%m-%dT%H:%M:%S")
)
The result:
2017-08-11T10:36:30
Related
I have a one to many relation between session and camp. Now I have to get the max and min dates of all camps combined for a particular session.
I am able to do it like this:
sess = Session.objects.last()
max_min_dates = sess.camp.aggregate(Min('start_date'), Max('end_date'))
But if I try to send this from HttpResponse then I am getting this error:
TypeError: Object of type 'date' is not JSON serializable
So I need to send the formatted date values in that. How can I modify the above code to get the same?
The default encoder for json.dumps() does not support date encoding (ie. can't convert date into str). You can use django encoder instead, it supports a few more data types see the link for more info.
Django Ref
import json
from django.core.serializers.json import DjangoJSONEncoder
json_str = json.dumps(max_min_dates, cls=DjangoJSONEncoder)
I'm testing with AjaxResponse with my request factory on a datetime. The problem is the string that Django gives is like this: 2020-08-27T22:46:07.354Z
But when I have datetime object, and I use the isoformat() method, I don't get the same string: 2020-08-27T22:46:07.354734+00:00
How am I going to be able to assert? I'm looking to assert by comparing the JSON with my own Python list (The list is what I can customize).
Thanks to Bast in Discord.py; the datetime conversion is not even iso8601 entirely... it's defined by ECMA-262 which is for JS:
from django.core.serializers.json import DjangoJSONEncoder
DjangoJSONEncoder().default(datetime_obj)
>>> '2020-08-28T03:41:59.194Z'
whereas using the .isoformat() method from standard lib would return 6 rather than 3 decimal points and use +00:00 rather than Z.
When using a JSONField, the contents are automatically decoded from JSON into python objects when reading the value. I have a use-case where I'm encoding the string back into JSON to embed in a template. Is there any way to just get the raw JSON string from the object?
Django uses psycopg2.extras.Json under the hood. You will need to cast the field as text to get the original out as plain text [1]. Use django's Cast function [2] to annotate your queryset:
from django.db.models.functions import Cast
from django.db.models import TextField
models_with_json_text = Model.objects.annotate(
json_as_text=Cast("json_field_name", TextField())
)
[1] http://initd.org/psycopg/docs/extras.html#json-adaptation
[2] https://docs.djangoproject.com/en/2.2/ref/models/database-functions/#cast
Code snippet
from dbinit import session
from geoalchemy2 import Geometry, func
result = session.query(func.ST_AsText('POINT(100 100)'))
How to retrieve the data from this result object?
I have figured out the solution.
re = result.all()
I'm using django-nonrel and mongodb to develop app. I know that object id is start with a timestamp of the insertion time of object creation. So it's possible to do time range query based on _id field.
How can I generate a minimal object_id based on a given time in python or django?
Here is a much more pythonic version of the other answer here provided by OP, along with documentation:
from bson.objectid import ObjectId
import datetime
def datetime_to_objectid(dt):
# ObjectId is a 12-byte BSON type, constructed using:
# a 4-byte value representing the seconds since the Unix epoch,
# a 3-byte machine identifier,
# a 2-byte process id, and
# a 3-byte counter, starting with a random value.
timestamp = int((dt - datetime.datetime(1970,1,1)).total_seconds())
time_bytes = format(timestamp, 'x') #4 bytes
return ObjectId(time_bytes+'00'*8) #+8 bytes
However, starting with version 1.6 of pymongo, it would be much more elegant to do the following:
from bson.objectid import ObjectId
ObjectId.from_datetime(dt)
from bson.objectid import ObjectId
import time
def get_minimal_object_id_for_int_timestamp(int_timestamp=None):
if not int_timestamp:
int_timestamp=int(time.time())
return ObjectId(hex(int(int_timestamp))[2:]+'0000000000000000')
def get_int_timestamp_from_time_string(time_string=None):
# format "YYYY-MM-DD hh:mm:ss" like '2012-01-05 13:01:51'
if not time_string:
return int(time.time())
return int(time.mktime(time.strptime(time_string, '%Y-%m-%d %H:%M:%S')))
def get_minimal_object_id_for_time_string(time_string=None):
return get_minimal_object_id_for_int_timestamp(get_int_timestamp_from_time_string(time_string=time_string))
I find the solution finally. hope it helps to others.