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

Question

In boto 2, you can write to an S3 object using these methods:

• Key.set_contents_from_string()
• Key.set_contents_from_file()
• Key.set_contents_fr

Answer 1

Here's a nice trick to read JSON from s3:

import json, boto3
s3 = boto3.resource("s3").Bucket("bucket")
json.load_s3 = lambda f: json.load(s3.Object(key=f).get()["Body"])
json.dump_s3 = lambda obj, f: s3.Object(key=f).put(Body=json.dumps(obj))

Now you can use json.load_s3 and json.dump_s3 with the same API as load and dump

data = {"test":0}
json.dump_s3(data, "key") # saves json to s3://bucket/key
data = json.load_s3("key") # read json from s3://bucket/key