Sync partiton APIs with collection (#1406)

See also: #1403

Signed-off-by: yangxuan <xuan.yang@zilliz.com>

pymilvus/client/prepare.py

@@ -255,7 +255,7 @@ def partition_name(cls, collection_name, partition_name):
     def batch_insert_param(cls, collection_name, entities, partition_name, fields_info=None, **kwargs):
         # insert_request.hash_keys won't be filled in client. It will be filled in proxy.
 
-        tag = partition_name or "_default" # should here?
+        tag = partition_name if isinstance(partition_name, str) else "_default"  # should here?
         insert_request = milvus_types.InsertRequest(collection_name=collection_name, partition_name=tag)
 
         for entity in entities:

pymilvus/orm/collection.py

@@ -128,7 +128,6 @@ def __init__(self, name: str, schema: CollectionSchema=None, using: str="default
     def __repr__(self):
         _dict = {
             'name': self.name,
-            'partitions': self.partitions,
             'description': self.description,
             'schema': self._schema,
         }