如何从字符串中获取 mongodb 的有效 object id？

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?

---

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?

Answer 1

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')

Answer 2

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

Answer 3

Assuming the string is in variable rndId , do the following:

from bson.objectid import ObjectId

rndId="1234"
collection.find_one({"_id": ObjectId(rndId)

*** Pre-install the bson package dependency:

> pip install bson