Function update

mongoengine/queryset/transform.py:238–418

Transform an update spec from Django-style format to Mongo format.

(_doc_cls=None, **update)

def update(_doc_cls=None, **update):
    """Transform an update spec from Django-style format to Mongo
    format.
    """
    mongo_update = {}

    for key, value in update.items():
        if key == "__raw__":
            handle_raw_query(value, mongo_update)
            continue

        parts = key.split("__")

        # if there is no operator, default to 'set'
        if len(parts) < 3 and parts[0] not in UPDATE_OPERATORS:
            parts.insert(0, "set")

        # Check for an operator and transform to mongo-style if there is
        op = None
        if parts[0] in UPDATE_OPERATORS:
            op = parts.pop(0)
            # Convert Pythonic names to Mongo equivalents
            operator_map = {
                "push_all": "pushAll",
                "pull_all": "pullAll",
                "dec": "inc",
                "add_to_set": "addToSet",
                "set_on_insert": "setOnInsert",
            }
            if op == "dec":
                # Support decrement by flipping a positive value's sign
                # and using 'inc'
                value = -value
            # If the operator doesn't found from operator map, the op value
            # will stay unchanged
            op = operator_map.get(op, op)

        match = None

        if len(parts) == 1:
            # typical update like set__field
            # but also allows to update a field named like a comparison operator
            # like set__type = "something" (without clashing with the 'type' operator)
            pass
        elif len(parts) > 1:
            # can be either an embedded field like set__foo__bar
            # or a comparison operator as in pull__foo__in
            if parts[-1] in COMPARISON_OPERATORS:
                match = parts.pop()  # e.g. pop 'in' from pull__foo__in

            # Allow to escape operator-like field name by __
            # e.g. in the case of an embedded foo.type field
            # Doc.objects().update(set__foo__type="bar")
            # see https://github.com/MongoEngine/mongoengine/pull/1351
            if parts[-1] == "":
                match = parts.pop()  # e.g. pop last '__' from set__foo__type__

        if _doc_cls: