Passing atributes in variables to $ operators

[nabil]

Hi,

How can I pass document attributes in variables to operators like
$set? I've tried this, but it looks like the __raw__ attribute is not
supported in update_one().

class Part(Document):
name = StringField()

foo = 'name'
# this should update the name attribute of the Part doc
Part.objects(...).update_one(__raw__={'$set' : {foo : 'bar'}})

Also, where can I found documentation on the underscore syntax?

Thanks

[Ross Lawley]

Hi,

You can use update_one(set__FIELDNAME=value) - theres some examples here: 

http://mongoengine.org/docs/v0.5/guide/querying.html#atomic-updates

Hope that helps

Ross

[nabil]

What if FIELDNAME is in a variable like in my example?

[Ross Lawley]

Hi,

Well then you can just pass it as a kwarg eg: **{"set__%s" % VAR: value}

Ross

[nabil]

Thanks. Forgot about kwargs.