How to get the list of all versions of the object from S3 present in AWS Resource

In this article, we will see how to get the list of all versions of objects from S3 using boto3 in Python. This is useful when S3 versioning is enabled and you need to track object history.

Prerequisites

Before running this code, ensure you have ?

• AWS credentials configured (via AWS CLI, IAM roles, or environment variables)

• S3 bucket with versioning enabled

• boto3 library installed: pip install boto3

Approach

We'll use the list_object_versions() method from the S3 client to retrieve all versions of objects in a specific bucket and prefix ?

• Step 1: Import boto3 and botocore for exception handling

• Step 2: Create an AWS S3 client

• Step 3: Use list_object_versions() with bucket name and prefix

• Step 4: Handle exceptions and return the results

Example

The following code lists all versions of objects in the testfolder prefix from Bucket_1 ?

import boto3
from botocore.exceptions import ClientError

def list_all_objects_version(bucket_name, prefix_name):
    session = boto3.session.Session()
    s3_client = session.client('s3')
    try:
        result = s3_client.list_object_versions(Bucket=bucket_name, Prefix=prefix_name)
        return result
    except ClientError as e:
        raise Exception("boto3 client error in list_all_objects_version function: " + str(e))
    except Exception as e:
        raise Exception("Unexpected error in list_all_objects_version function: " + str(e))

# List all versions of objects in testfolder
versions = list_all_objects_version("Bucket_1", "testfolder")
print(versions)

Understanding the Output

The response contains several important fields ?

• Versions: Array of all object versions with metadata

• Key: Object path (e.g., "testfolder/test.zip")

• VersionId: Unique version identifier

• IsLatest: Boolean indicating if this is the current version

• LastModified: Timestamp when the version was created

• Size: Object size in bytes

Extracting Specific Version Information

To work with specific versions, you can iterate through the results ?

import boto3
from botocore.exceptions import ClientError
from datetime import datetime

def get_object_versions_info(bucket_name, prefix_name):
    session = boto3.session.Session()
    s3_client = session.client('s3')
    
    try:
        result = s3_client.list_object_versions(Bucket=bucket_name, Prefix=prefix_name)
        
        versions_info = []
        for version in result.get('Versions', []):
            version_info = {
                'Key': version['Key'],
                'VersionId': version['VersionId'],
                'IsLatest': version['IsLatest'],
                'Size': version['Size'],
                'LastModified': version['LastModified'].strftime('%Y-%m-%d %H:%M:%S')
            }
            versions_info.append(version_info)
        
        return versions_info
        
    except ClientError as e:
        print(f"Error: {e}")
        return []

# Example usage
versions = get_object_versions_info("my-bucket", "documents/")
for version in versions[:3]:  # Show first 3 versions
    print(f"Key: {version['Key']}")
    print(f"Version ID: {version['VersionId']}")
    print(f"Is Latest: {version['IsLatest']}")
    print(f"Size: {version['Size']} bytes")
    print(f"Last Modified: {version['LastModified']}")
    print("-" * 40)

Key: documents/report.pdf
Version ID: 3/L4kqtJlcpXroDVBH40Nr8X8gdRQBpUMLUo
Is Latest: True
Size: 245760
Last Modified: 2024-01-15 10:30:25
----------------------------------------
Key: documents/report.pdf
Version ID: 47DEQpj8HBSa.OVBj0HQSQ2E
Is Latest: False
Size: 198432
Last Modified: 2024-01-10 14:22:18
----------------------------------------
Key: documents/data.csv
Version ID: null
Is Latest: True
Size: 15840
Last Modified: 2024-01-12 09:15:33
----------------------------------------

Key Parameters

Conclusion

Use list_object_versions() to retrieve all versions of S3 objects when versioning is enabled. This method returns comprehensive metadata including version IDs, modification dates, and size information for tracking object history.