python – How to write a file or data to an S3 object using boto3

In boto 3, the Key.set_contents_from_ methods were replaced by

• Object.put()

• Client.put_object()

For example:

import boto3

some_binary_data = bHere we have some data
more_binary_data = bHere we have some more data

# Method 1: Object.put()
s3 = boto3.resource(s3)
object = s3.Object(my_bucket_name, my/key/including/filename.txt)
object.put(Body=some_binary_data)

# Method 2: Client.put_object()
client = boto3.client(s3)
client.put_object(Body=more_binary_data, Bucket=my_bucket_name, Key=my/key/including/anotherfilename.txt)

Alternatively, the binary data can come from reading a file, as described in the official docs comparing boto 2 and boto 3:

Storing Data

Storing data from a file, stream, or string is easy:

# Boto 2.x
from boto.s3.key import Key
key = Key(hello.txt)
key.set_contents_from_file(/tmp/hello.txt)

# Boto 3
s3.Object(mybucket, hello.txt).put(Body=open(/tmp/hello.txt, rb))

boto3 also has a method for uploading a file directly:

s3 = boto3.resource(s3)    
s3.Bucket(bucketname).upload_file(/local/file/here.txt,folder/sub/path/to/s3key)

http://boto3.readthedocs.io/en/latest/reference/services/s3.html#S3.Bucket.upload_file

python – How to write a file or data to an S3 object using boto3

You no longer have to convert the contents to binary before writing to the file in S3. The following example creates a new text file (called newfile.txt) in an S3 bucket with string contents:

import boto3

s3 = boto3.resource(
    s3,
    region_name=us-east-1,
    aws_access_key_id=KEY_ID,
    aws_secret_access_key=ACCESS_KEY
)
content=String content to write to a new S3 file
s3.Object(my-bucket-name, newfile.txt).put(Body=content)