How would I return just the string component of an BSON ObjectId using pymongo. I'm able to encode a string into an Object id by importing ObjectId from bson.objectid; but am unable to do the reverse.
When I try:
for post in db.votes.find({'user_id':userQuery['_id']}):
posts += post['_id'].str
I get an ObjectId has no attribute str error.
Thanks!
The standard way in python to get object's string representation is using the str builtin function:
id = bson.objectid.ObjectId()
str(id)
=> '5190666674d3cc747cc12e61'
try this:
for post in db.votes.find({'user_id':userQuery['_id']}):
posts += str(post['_id'])
BTW, you can use MongoKit to deal with the special bson data structure.
from bson.objectid import ObjectId
class CustomObjectId(CustomType):
mongo_type = ObjectId # optional, just for more validation
python_type = str
init_type = None # optional, fill the first empty value
def to_bson(self, value):
"""convert type to a mongodb type"""
return ObjectId(value)
def to_python(self, value):
"""convert type to a python type"""
return str(value)
def validate(self, value, path):
"""OPTIONAL : useful to add a validation layer"""
if value is not None:
pass # ... do something here
This custom ObjectId can turn the bson ObjectId to python str.
Visit http://mongokit.readthedocs.org/mapper.html#the-structure for more information.
Related
This question already has an answer here:
Change type from string to float/double for a key value of any json object in an array
(1 answer)
Closed 1 year ago.
I'm trying to convert an Array to string using a simple js function placed in the reusable feature file. I don't see any reason why the array is not getting converted to a string when I try to run the same function on the console it works without any issue.
Can anyone suggest a way to get this issue sorted?
"""
* def formatter = function(str){
var formatstring = str.toString();
return formatstring
}
"""
feature file
* def format = call read('../common/resuable.feature)
* def result = format.formatter(value)
* print result
Input = ["ID3:Jigglypuff(NORMAL)"]
Actual result = ["ID3:Jigglypuff(NORMAL)"]
Expected result = ID3:Jigglypuff(NORMAL)
[![When tried same on console][1]][1]
[1]: https://i.stack.imgur.com/tAcIz.png
Sorry, if you print an array, it will have square-brackets and all, that's just how it is.
Please unpack arrays if you want the plain string / content:
* def input = ["ID3:Jigglypuff(NORMAL)"]
* def expected = input[0]
How do I annotate a Django queryset with a Regex capture group without using RawSQL so that I later can use that value for filtering and sorting?
For example, in PostgreSQL I could make the following query:
CREATE TABLE foo (id varchar(100));
INSERT INTO foo (id) VALUES ('disk1'), ('disk10'), ('disk2');
SELECT
"foo"."id",
CAST((regexp_matches("foo"."id", '^(.*\D)([0-9]*)$'))[2] AS integer) as grp2
FROM "foo"
ORDER BY "grp2"
dbfiddle
You can use a custom Func class created to get it working, but I would like to implement in a better way, just like a normal function which could be used for further processing using other functions or annotations or etc. Like a "block" in the Django ORM ecosystem.
I would like to start with an "beta version" of the class which looks like this one:
from django.db.models.expressions import Func, Value
class RegexpMatches(Func):
function = 'REGEXP_MATCHES'
def __init__(self, source, regexp, flags=None, group=None, output_field=None, **extra):
template = '%(function)s(%(expressions)s)'
if group:
if not hasattr(regexp, 'resolve_expression'):
regexp = Value(regexp)
template = '({})[{}]'.format(template, str(group))
expressions = (source, regexp)
if flags:
if not hasattr(flags, 'resolve_expression'):
flags = Value(flags)
expressions += (flags,)
self.template = template
super().__init__(*expressions, output_field=output_field, **extra)
and a fully working example for an admin interface:
from django.contrib.admin import ModelAdmin, register
from django.db.models import IntegerField
from django.db.models.functions import Cast
from django.db.models.expressions import Func, Value
from .models import Foo
class RegexpMatches(Func):
function = 'REGEXP_MATCHES'
def __init__(self, source, regexp, flags=None, group=None, output_field=None, **extra):
template = '%(function)s(%(expressions)s)'
if group:
if not hasattr(regexp, 'resolve_expression'):
regexp = Value(regexp)
template = '({})[{}]'.format(template, str(group))
expressions = (source, regexp)
if flags:
if not hasattr(flags, 'resolve_expression'):
flags = Value(flags)
expressions += (flags,)
self.template = template
super().__init__(*expressions, output_field=output_field, **extra)
#register(Foo)
class Foo(ModelAdmin):
list_display = ['id', 'required_field', 'required_field_string']
def get_queryset(self, request):
qs = super().get_queryset(request)
return qs.annotate(
required_field=Cast(RegexpMatches('id', r'^(.*\D)([0-9]*)$', group=2), output_field=IntegerField()),
required_field_string=RegexpMatches('id', r'^(.*\D)([0-9]*)$', group=2)
)
def required_field(self, obj):
return obj.required_field
def required_field_string(self, obj):
return obj.required_field_string
As you see in I've added 2 annotations and one outputs like a number and the other one like a normal string (character), of course, we don't see it in the admin interface but it does in the SQL are executed:
SELECT "test_foo"."id" AS Col1,
((REGEXP_MATCHES("test_foo"."id", '^(.*\D)([0-9]*)$'))[2])::integer AS "required_field", (REGEXP_MATCHES("test_foo"."id", '^(.*\D)([0-9]*)$'))[2] AS "required_field_string"
FROM "test_foo"
And also a screenshot with an example for you :)
Github gist with a better source code formatting https://gist.github.com/phpdude/50675114aaed953b820e5559f8d22166
From Django 1.8 onwards, you can use Func() expressions.
from django.db.models import Func
class EndNumeric(Func):
function = 'REGEXP_MATCHES'
template = "(%(function)s(%(expressions)s, '^(.*\D)([0-9]*)$'))[2]::integer"
qs = Foo.objects.annotate(
grp2=EndNumeric('id'),
).values('id', 'grp2').order_by('grp2')
Reference: Get sorted queryset by specified field with regex in django
I have a model, where I want to access a field, given by a string. Example:
def test(self):
field = 'name'
name = getattr(self, field)
This works fine - name is set to self.name. But then I want to access a related field:
def test2(self):
field = 'partner_id.name'
name = getattr(self, field)
That doesn't work (because 'partner_id.name' does not exist on self). Any idea how to do it right?
getattr doesn't support the dot notation, only simple attribute names. You can however create a simple function that does:
def getfield(model, field_name):
value = model
for part in field_name.split('.'):
value = getattr(value, part)
return value
You would use it like this:
def test2(self):
field = 'partner_id.name'
name = getfield(self, field)
You need to use the object that contain partner_id.name
def test2(self):
field = 'name'
object = self.pool.get('res.partner').browse(cr, uid, self.partner_id.id)#v7
#object = self.env['res.partner'].browse(self.partner_id.id)#v8
name = getattr(object, field)
I also came across another solution, inspired by the mail template system:
from openerp.tools.safe_eval import safe_eval as eval
def test2(self):
field = 'partner_id.name'
field = 'object.' + field
name = eval(field, {'object': self})
I want to get the string character from an ObjectId object. I use pymongo.
eg: ObjectId("543b591d91b9e510a06a42e2"), I want to get "543b591d91b9e510a06a42e2".
I see the doc, It says ObjectId.toString(), ObjectId.valueOf().
So I make this code: from bson.objectid import ObjectId.
But when I use ObjectId.valueOf(), It shows:
'ObjectId' object has no attribute 'valueOf'.
How can I get it? Thanks.
ObjectId.toString() and ObjectId.valueOf() are in Mongo JavaScript API.
In Python API (with PyMongo) proper way is to use pythonic str(object_id) as you suggested in comment, see documentation on ObjectId.
ObjectId.toString() returns the string representation of the ObjectId() object.
In pymongo str(o) get a hex encoded version of ObjectId o.
Check this link.
What works for me is to "sanitize" the output so Pydantic doesn't get indigestion from an _id that is of type ObjectId...here's what works for me...
I'm converting _id to a string before returning the output...
# Get One
#router.get("/{id}")
def get_one(id):
query = {"_id": ObjectId(id)}
resp = db.my_collection.find_one(query)
if resp:
resp['_id'] = str(resp['_id'])
return resp
else:
raise HTTPException(status_code=404, detail=f"Unable to retrieve record")
Use str(ObjectId), as already mentined in the comment by #Simon.
#app.route("/api/employee", methods=['POST'])
def create_employee():
json = request.get_json()
result = employee.insert_employee(json)
return { "id": str(result.inserted_id) }
This is an old thread, but as the existing answers didn't help me:
Having run
new_object = collection.insert_one(doc)
I was able to get the ObjectID with the inserted_id property:
print(f"{new_object.inserted_id}")
In python (Pymongo) there's no inbuilt method to do it so iterate over the result you fetched from db and then typecast _id to str(_id)
result = collection.find({query})
for docs in result:
docs[_id] = str(docs[_id])
first you have to assign the Object Id value to a variable
for example:
let objectId = ObjectId("543b591d91b9e510a06a42e2");
then use the toString method like this
let id = objectId.toString();
I have the following model:
class UptimeManager(models.Manager):
def with_length(self):
"""Get querySet of uptimes sorted by length including the current one. """
extra_length = Uptime.objects.extra(select={'length':
"""
SELECT
IF (end is null,
timestampdiff(second,begin,now()),
timestampdiff(second,begin,end))
FROM content_uptime c
WHERE content_uptime.id = c.id
"""
})
return extra_length
class Uptime(models.Model):
begin = models.DateTimeField('beginning')
end = models.DateTimeField('end', null=True) I call
host = models.ForeignKey("Host")
objects = UptimeManager()
...
then I call Uptime.objects.with_length().order_by('-length')[:10] to get list of longest uptimes.
But the length in template is of integer type. How to modify my code as the length of object returned by manager would be accessible in template as timedelta object?
I almost could do it by returning a list and converting number of seconds to timedelta objects, but then I have to do sorting, filtering etc. in my Python code which is rather ineffective in comparison to one well done SQL query.
Add a property to the model that looks at the actual field and converts it to the appropriate type.
My solution is to create a filter that determines type of length var and returns timedelta in case it's some integer type
from django import template
import datetime
register = template.Library()
def timedelta(value):
if isinstance(value, (long,int)):
return datetime.timedelta(seconds=value)
elif isinstance(value, datetime.timedelta):
return value
else: raise UnsupportedOperation
register.filter('timedelta',timedelta)
and use in template it's trivial
{{ uptime.length|timedelta }}