Collection.find does not work in 7.6.1 if filter attribute is set to none

[sushi2all]

Hello,

I have a piece of code searching for records that DO NOT have a certain attribute, in the following way:

match = dict(
 canceled = None, 
 #...some other stuff
)
cursor = self.tx.collection('Whatever').find(match)

This was working fine up to a while ago. Today a customer called me saying that a feature wasn't working. I had just upgraded to the latest version of python arango, and using a previous version the bug didn't appear (I know, I should have tests in place, I'll get to them someday 😓).

The error is the following:

arango.exceptions.DocumentGetError: [HTTP 400][ERR 1501] AQL: syntax error, unexpected none modifier near 'None\n LIMIT 0, nu...' at position 3:69 (while parsing)

I looked weird that it mentioned a query. I checked the python-arango code and noticed that in the latest release the code for find changed in 022afc2 from this:

data: Json = {
    "collection": self.name,
    "example": filters,
    "skip": skip,
}
if limit is not None:
    data["limit"] = limit

request = Request(
    method="put", endpoint="/_api/simple/by-example", data=data, read=self.name
)

def response_handler(resp: Response) -> Cursor:
    if not resp.is_success:
        raise DocumentGetError(resp, request)
    return Cursor(self._conn, resp.body)

return self._execute(request, response_handler)

to this

skip_val = skip if skip is not None else 0
limit_val = limit if limit is not None else "null"
query = f"""
    FOR doc IN @@collection
        {build_filter_conditions(filters)}
        LIMIT {skip_val}, {limit_val}
        RETURN doc
"""

bind_vars = {"@collection": self.name}

request = Request(
    method="post",
    endpoint="/_api/cursor",
    data={"query": query, "bindVars": bind_vars, "count": True},
    read=self.name,
    headers={"x-arango-allow-dirty-read": "true"} if allow_dirty_read else None,
)

def response_handler(resp: Response) -> Cursor:
    if not resp.is_success:
        raise DocumentGetError(resp, request)
    return Cursor(self._conn, resp.body)

return self._execute(request, response_handler)

@aMahanna: Is this a regression or dict(attribute=None) as filter is not meant to work? In the second case, is there any other solution or workaround?

[aMahanna]

Hi @sushi2all, the fix for this has been addressed in #277

Will be triggering a 7.6.2 release now, so this should solve the issue

[aMahanna]

7.6.2 released: https://pypi.org/project/python-arango/7.6.2/

[sushi2all]

Thank you!