how can I get a valid object id of mongodb from a string?

Question

I want to make my mongodb OjectId to a field:

class ZhinengStats(Document):
    zhineng_id = ObjectIdField(db_field="_id", primary_key=True, required=True, help_text="job id")

but a valid ObjectId must be a 12-byte input of type 'str' or a 24-character hex string, so if I do this:

ZhinengStats.objects(zhineng_id="programmer").first()

I will get an error. I thought a hash is a good way:

hash("programmer") # 7354308922443094682

but as you can see, hash seems not ok.

So how can I get a valid object id?

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UPDATE:

the main problem is because this is field is a chinese, so something like this:ObjectId('兼职'.decode("utf-8")) can not work, so how can I make this support utf-8?

Solution 1

Is there any reason why you must generate the ObjectId from a string? If you simply wants an unique id for your mongodb document, you can generate one automatically like so

from bson.objectid import ObjectId
_id = ObjectId()

the ObjectId generated will be based on the machine's hardware signature, and the current time

Solution 2

Python mongodb documentation has examples ready for you:

class bson.objectid.ObjectId(oid=None)

Initialize a new ObjectId.

ObjectId(b'foo-bar-quux')
ObjectId('666f6f2d6261722d71757578')

Comments

[Sylvain Leroux]

Python 2 or Python 3 ?

[roger]

@SylvainLeroux python 2

[Bacar Pereira]

Check this link will help you stackoverflow.com/a/66117385/9416032

[roger]

I have a problem with this, chinese is not ok, such as ObjectId(u"兼职") returns bson.errors.InvalidId: u'\u517c\u804c' is not a valid ObjectId, it must be a 12-byte input of type 'str' or a 24-character hex string

[Salvador Dali]

@roger may be this will help: stackoverflow.com/questions/24571790/…

[roger]

you mean ObjectId("兼职".decode("utf-8"))? this can not work.