light-s3-client

Purpose

The AWS Boto3 Client is quite heavy, and usually specific functionality is needed. This module only implements needed functionality using the requests library and the S3 REST API.

Reference doc used for this creation: https://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html#signing-request-intro

Note: The parameter names and function names were copied from the Boto3 S3 Client. It does not necessarily have all the options for the function

Supported Functions

Client.download_file(Bucket, Key, Filename)

Download an S3 object to a file.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
s3.download_file("mybucket", "hello.txt", "/tmp/hello.txt")

PARAMETERS:

• Bucket (str) – The name of the bucket to download from.
• Key (str) – The name of the key to download from.
• Filename (str) – The path to the file to download to.

Client.upload_fileobj(Fileobj, Bucket, Key)

Upload a file object to S3. The Content-Type header is automatically inferred from the file extension.

Usage:

from light_s3_client import Client
import json


def get_file_contents(file_name) -> bytes:
    file_handle = open(file_name, "r")
    content = json.load(file_handle)
    str_content = json.dumps(content)
    file_handle.close()
    data = str_content.encode("utf-8")
    return data


s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
upload_data = get_file_contents("example.json")
s3.upload_fileobj(upload_data, "example-bucket", "path/example.json")

PARAMETERS:

• Fileobj (bytes, io.BytesIO, io.BufferedReader, or io.TextIOWrapper) – A file-like object or bytes to upload.
• Bucket (str) – The name of the bucket to upload to.
• Key (str) – The name of the key to upload to.

Client.upload_file_multipart(Fileobj, Bucket, Key, part_size, max_parts)

Upload a file to S3 using multipart upload for large files. Falls back to regular upload if the file is smaller than part_size.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
with open("large_file.bin", "rb") as f:
    s3.upload_file_multipart(f, "example-bucket", "path/large_file.bin")

PARAMETERS:

• Fileobj (bytes, io.BytesIO, io.BufferedReader, or io.TextIOWrapper) – A file-like object or bytes to upload.
• Bucket (str) – The name of the bucket to upload to.
• Key (str) – The name of the key to upload to.
• part_size (int, optional) – Size of each part in bytes. Default is 5MB (5242880).
• max_parts (int, optional) – Maximum number of parts allowed. Default is 10000.

Client.delete_file(Bucket, Key)

Delete an S3 object. Returns True if the deletion was successful, False otherwise.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
result = s3.delete_file("example-bucket", "path/example.json")
print(f"Delete result: {result}")  # True if successful, False otherwise

Client.list_objects(Bucket, Prefix)

List all keys in an S3 bucket with a given prefix.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
objects = s3.list_objects("example-bucket", "path/")
print(f"Found {len(objects)} objects")

Client.get_object(Bucket, Key)

Check if an S3 object exists. Returns True if the object exists, False otherwise.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
exists = s3.get_object("example-bucket", "path/example.json")
print(f"Object exists: {exists}")  # True if exists, False otherwise

Client.head_object(Bucket, Key)

Check if an S3 object exists and return its metadata. Returns a dictionary with metadata if the object exists, or an empty dictionary otherwise.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
metadata = s3.head_object("example-bucket", "path/example.json")
print(f"Object metadata: {metadata}")  # Dictionary with metadata or empty dict

Client.put_object_tagging(Bucket, Key, Tags)

Set tags for an S3 object. Returns True if successful, False otherwise.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
tags = {"Environment": "Production", "Owner": "John Doe"}
result = s3.put_object_tagging("example-bucket", "path/example.json", tags)
print(f"Tagging result: {result}")  # True if successful, False otherwise

Client.get_object_tagging(Bucket, Key)

Retrieve tags for an S3 object. Returns a dictionary of tag key-value pairs if successful, or an empty dictionary otherwise.

Usage:

from light_s3_client import Client

s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)
tags = s3.get_object_tagging("example-bucket", "path/example.json")
print(f"Object tags: {tags}")  # Dictionary with tags or empty dict

Client Initialization Parameters

Authentication

This library implements AWS Signature Version 4 authentication by default, following the same signing standard as boto3. Legacy Signature Version 2 is also supported.

Usage:

from light_s3_client import Client

# Default: Signature V4 (recommended, works with AWS and modern MinIO)
s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME"
)

# Legacy: Signature V2 (for older S3-compatible services)
s3 = Client(
    region="us-west-1",
    access_key="REPLACE_ME",
    secret_key="REPLACE_ME",
    signature_version="v2"
)

# Custom S3-compatible server (e.g. MinIO)
s3 = Client(
    region="us-east-1",
    access_key="minioadmin",
    secret_key="minioadmin",
    server="http://localhost:9000"
)