title: MongoDB projection - take first element from Array
body: <p>My field &quot;Field1.Field2&quot; is an array and I want to take only first element of this array, i.e. &quot;Field1.Field2.0&quot; and from this I want to take any other given field for example: &quot;Field1.Field2.0.Field3&quot;. Unfortunately when I use this projection in  PyMongo then it doesn't work (this &quot;0&quot; make problems). The projection doesn't throw an error but the field &quot;0&quot; doesnt contain any values after projection while it contain the values before projection. What may be the reason?</p>