Boto3 S3 Transfer

Best Practices for Uploading and Downloading Files

Boto3 is the Amazon Web Services (AWS) SDK for Python, which provides Python developers with an easy-to-use interface to access AWS services. Boto3 allows Python developers to create, configure, and manage AWS services like S3, EC2, DynamoDB, and more.

Installation

To use Boto3, you first need to install it and its dependencies.

pip install boto3

Configuration

Before using Boto3, you must set up authentication credentials for your AWS account using either the IAM Console or the AWS CLI. You can either choose an existing user or create a new one. AWS configuration will be very helpful while using boto3.

To configure AWSCLI in your system follow the instructions in AWS Documentations depending on your system.

If you have the AWS CLI installed, then you can use the command:

aws configure

This command will ask for an access key and a security key which you can generate from the IAM console. This completes the configuration.

Using Boto3 for S3

Once Boto3 is installed, you can begin interacting with S3 using Python code.

Listing S3 Buckets

To list all the buckets you can use the ‘list_buckets()’ method of S3 resources.

import boto3

s3 = boto3.client('s3')

response = s3.list_buckets()

for bucket in response['Buckets']:
    print(f'{bucket["Name"]}')

Uploading a File to S3

To upload a file to S3 using Boto3, you can use the upload_file() method of the S3 resource. The upload_file() method takes the following parameters:

• Filepath: The local file path of the file you want to upload to S3.
• Bucket: The name of the S3 bucket you want to upload the file to.
• Key: The name you want to give the file when uploaded to S3.

import boto3

s3 = boto3.resource('s3')

bucket_name = 'my-s3-bucket'
file_path = '/path/to/my/file.txt'
object_key = 'file.txt'

s3.Object(bucket_name, object_key).upload_file(file_path)

Downloading a File from S3

To download a file from S3 using Boto3, you can use the download_file() method of the S3 resource. The download_file() method takes the following parameters:

• Bucket: The name of the S3 bucket you want to download the file from.
• Key: The name of the file you want to download from S3.
• Filename: The local file path where you want to save the downloaded file.

import boto3

s3 = boto3.resource('s3')

bucket_name = 'my-s3-bucket'
object_key = 'file.txt'
local_file_path = '/path/to/local/file.txt'

s3.Object(bucket_name, object_key).download_file(local_file_path)

All these programs will only use the access key and security key that you have configured. If you want to change it in the code itself you can use boto3.client() and boto3.resource() and pass the access key, security key, and region as its parameters.

s3_client = boto3.client('s3', 
                         aws_access_key_id=access_key, 
                         aws_secret_access_key=secret_key, 
                         region_name=region_name)

Conclusion

Boto3 is a powerful Python library that makes it easy to work with AWS services. In this article, we covered the basics of using Boto3 to access AWS services in S3. Boto3 provides a rich set of features that you can use to build sophisticated applications that leverage AWS services.