python-boto3/docs/source/guide/s3-uploading-files.rst
2021-09-22 09:34:33 -07:00

163 lines
5.2 KiB
ReStructuredText

.. Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0
International License (the "License"). You may not use this file except in compliance with the
License. A copy of the License is located at http://creativecommons.org/licenses/by-nc-sa/4.0/.
This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
either express or implied. See the License for the specific language governing permissions and
limitations under the License.
###############
Uploading files
###############
The AWS SDK for Python provides a pair of methods to upload a file to an S3
bucket.
The ``upload_file`` method accepts a file name, a bucket name, and an object
name. The method handles large files by splitting them into smaller chunks
and uploading each chunk in parallel.
.. code-block:: python
import logging
import boto3
from botocore.exceptions import ClientError
import os
def upload_file(file_name, bucket, object_name=None):
"""Upload a file to an S3 bucket
:param file_name: File to upload
:param bucket: Bucket to upload to
:param object_name: S3 object name. If not specified then file_name is used
:return: True if file was uploaded, else False
"""
# If S3 object_name was not specified, use file_name
if object_name is None:
object_name = os.path.basename(file_name)
# Upload the file
s3_client = boto3.client('s3')
try:
response = s3_client.upload_file(file_name, bucket, object_name)
except ClientError as e:
logging.error(e)
return False
return True
The ``upload_fileobj`` method accepts a readable file-like object. The file
object must be opened in binary mode, not text mode.
.. code-block:: python
s3 = boto3.client('s3')
with open("FILE_NAME", "rb") as f:
s3.upload_fileobj(f, "BUCKET_NAME", "OBJECT_NAME")
The ``upload_file`` and ``upload_fileobj`` methods are provided by the S3
``Client``, ``Bucket``, and ``Object`` classes. The method functionality
provided by each class is identical. No benefits are gained by calling one
class's method over another's. Use whichever class is most convenient.
The ExtraArgs parameter
===========================
Both ``upload_file`` and ``upload_fileobj`` accept an optional ``ExtraArgs``
parameter that can be used for various purposes. The list of valid
``ExtraArgs`` settings is specified in the ``ALLOWED_UPLOAD_ARGS`` attribute
of the ``S3Transfer`` object
at :py:attr:`boto3.s3.transfer.S3Transfer.ALLOWED_UPLOAD_ARGS`.
The following ``ExtraArgs`` setting specifies metadata to attach to the S3
object.
.. code-block:: python
s3.upload_file(
'FILE_NAME', 'BUCKET_NAME', 'OBJECT_NAME',
ExtraArgs={'Metadata': {'mykey': 'myvalue'}}
)
The following ``ExtraArgs`` setting assigns the canned ACL (access control
list) value 'public-read' to the S3 object.
.. code-block:: python
s3.upload_file(
'FILE_NAME', 'BUCKET_NAME', 'OBJECT_NAME',
ExtraArgs={'ACL': 'public-read'}
)
The ``ExtraArgs`` parameter can also be used to set custom or multiple ACLs.
.. code-block:: python
s3.upload_file(
'FILE_NAME', 'BUCKET_NAME', 'OBJECT_NAME',
ExtraArgs={
'GrantRead': 'uri="http://acs.amazonaws.com/groups/global/AllUsers"',
'GrantFullControl': 'id="01234567890abcdefg"',
}
)
The Callback parameter
==========================
Both ``upload_file`` and ``upload_fileobj`` accept an optional ``Callback``
parameter. The parameter references a class that the Python SDK invokes
intermittently during the transfer operation.
Invoking a Python class executes the class's ``__call__`` method. For each
invocation, the class is passed the number of bytes transferred up
to that point. This information can be used to implement a progress monitor.
The following ``Callback`` setting instructs the Python SDK to create an
instance of the ``ProgressPercentage`` class. During the upload, the
instance's ``__call__`` method will be invoked intermittently.
.. code-block:: python
s3.upload_file(
'FILE_NAME', 'BUCKET_NAME', 'OBJECT_NAME',
Callback=ProgressPercentage('FILE_NAME')
)
An example implementation of the ``ProcessPercentage`` class is shown below.
.. code-block:: python
import os
import sys
import threading
class ProgressPercentage(object):
def __init__(self, filename):
self._filename = filename
self._size = float(os.path.getsize(filename))
self._seen_so_far = 0
self._lock = threading.Lock()
def __call__(self, bytes_amount):
# To simplify, assume this is hooked up to a single filename
with self._lock:
self._seen_so_far += bytes_amount
percentage = (self._seen_so_far / self._size) * 100
sys.stdout.write(
"\r%s %s / %s (%.2f%%)" % (
self._filename, self._seen_so_far, self._size,
percentage))
sys.stdout.flush()