command_cursor – Tools for iterating over MongoDB command results — PyMongo 3.11.0 documentation (original) (raw)

CommandCursor class to iterate over command results.

class pymongo.command_cursor. CommandCursor(collection, cursor_info, address, retrieved=0, batch_size=0, max_await_time_ms=None, session=None, explicit_session=False)¶

Create a new command cursor.

The parameter ‘retrieved’ is unused.

address¶

The (host, port) of the server used, or None.

New in version 3.0.

alive¶

Does this cursor have the potential to return more data?

Even if alive is True, next() can raiseStopIteration. Best to use a for loop:

for doc in collection.aggregate(pipeline): print(doc)

Note

alive can be True while iterating a cursor from a failed server. In this case alive will return False afternext() fails to retrieve the next batch of results from the server.

batch_size(batch_size)¶

Limits the number of documents returned in one batch. Each batch requires a round trip to the server. It can be adjusted to optimize performance and limit data transfer.

Note

batch_size can not override MongoDB’s internal limits on the amount of data it will return to the client in a single batch (i.e if you set batch size to 1,000,000,000, MongoDB will currently only return 4-16MB of results per batch).

Raises TypeError if batch_size is not an integer. Raises ValueError if batch_size is less than 0.

close()¶

Explicitly close / kill this cursor.

cursor_id¶

Returns the id of the cursor.

next()¶

Advance the cursor.

session¶

The cursor’s ClientSession, or None.

New in version 3.6.

class pymongo.command_cursor. RawBatchCommandCursor(collection, cursor_info, address, retrieved=0, batch_size=0, max_await_time_ms=None, session=None, explicit_session=False)¶

Create a new cursor / iterator over raw batches of BSON data.

Should not be called directly by application developers - see aggregate_raw_batches()instead.

See also

The MongoDB documentation on

cursors