awswrangler.s3.size_objects(path: Union[str, List[str]], version_id: Optional[Union[str, Dict[str, str]]] = None, use_threads: Union[bool, int] = True, s3_additional_kwargs: Optional[Dict[str, Any]] = None, boto3_session: Optional[Session] = None) Dict[str, Optional[int]]

Get the size (ContentLength) in bytes of Amazon S3 objects from a received S3 prefix or list of S3 objects paths.

This function accepts Unix shell-style wildcards in the path argument. * (matches everything), ? (matches any single character), [seq] (matches any character in seq), [!seq] (matches any character not in seq). If you want to use a path which includes Unix shell-style wildcard characters (*, ?, []), you can use glob.escape(path) before passing the path to this function.


In case of use_threads=True the number of threads that will be spawned will be gotten from os.cpu_count().

  • path (Union[str, List[str]]) – S3 prefix (accepts Unix shell-style wildcards) (e.g. s3://bucket/prefix) or list of S3 objects paths (e.g. [s3://bucket/key0, s3://bucket/key1]).

  • version_id (Optional[Union[str, Dict[str, str]]]) – Version id of the object or mapping of object path to version id. (e.g. {‘s3://bucket/key0’: ‘121212’, ‘s3://bucket/key1’: ‘343434’})

  • use_threads (bool, int) – True to enable concurrent requests, False to disable multiple threads. If enabled os.cpu_count() will be used as the max number of threads. If integer is provided, specified number is used.

  • s3_additional_kwargs (Optional[Dict[str, Any]]) – Forwarded to botocore requests. e.g. s3_additional_kwargs={‘RequestPayer’: ‘requester’}

  • boto3_session (boto3.Session(), optional) – Boto3 Session. The default boto3 session will be used if boto3_session receive None.


Dictionary where the key is the object path and the value is the object size.

Return type

Dict[str, Optional[int]]


>>> import awswrangler as wr
>>> sizes0 = wr.s3.size_objects(['s3://bucket/key0', 's3://bucket/key1'])  # Get the sizes of both objects
>>> sizes1 = wr.s3.size_objects('s3://bucket/prefix')  # Get the sizes of all objects under the received prefix