Backblaze B2 SDK

2.10.4 · active · verified Wed Apr 15

The `b2sdk` library provides a comprehensive Python SDK for interacting with Backblaze B2 Cloud Storage. It allows developers to manage buckets, upload and download files, handle file versions, and more. The current version is 2.10.4, with releases occurring regularly to add features, fix bugs, and maintain compatibility.

Warnings

breaking Python 3.8 support was dropped in `b2sdk` v2.10.0. Projects using `b2sdk` must now run on Python 3.9 or newer.
Fix: Upgrade your Python environment to 3.9 or later.
gotcha The recommended API version for `b2sdk` is `v3` since `v2.9.1`. Importing `B2Api` from `b2sdk` directly (i.e., `from b2sdk import B2Api`) will use the older `v2` API, which may lack new features or lead to future compatibility issues.
Fix: Update imports to `from b2sdk.v3 import B2Api` for new projects or when updating existing code.
gotcha If using `SqliteAccountInfo` for local credential caching, upgrading to `b2sdk` v2.10.3 from an older version might encounter backwards compatibility issues due to changes in the sqlite schema related to multi-bucket key support.
Fix: If encountering issues after upgrading, try deleting the local account info file (typically `~/.b2_account_info`) and re-authorizing, or consult the `b2sdk` migration guide if available.
gotcha A retry bug in `upload_unbound_stream()` for small-file uploads could cause a `ValueError: I/O operation on closed file` if a retryable upload error occurred.
Fix: Upgrade to `b2sdk` v2.10.4 or later to fix this retry behavior.
gotcha The `b2sdk` library adapted `authorize_account` and key management flows for multi-bucket keys in `v2.9.1`. If you manage application keys that are scoped to multiple buckets, older integrations might need review.
Fix: Review key management logic and ensure it aligns with the multi-bucket key capabilities introduced in `v2.9.1`.

Install

pip install b2sdk Install latest version

Imports

B2Api
```
from b2sdk.v3 import B2Api
```
Since v2.9.1, the B2 SDK officially recommends importing from `b2sdk.v3` for the latest API interface and features. Importing from `b2sdk` directly (which maps to `v2`) is still supported but may not receive new features or might be deprecated in the future.
SqliteAccountInfo
```
from b2sdk.v3.account_info.sqlite_account_info import SqliteAccountInfo
```
Used for persisting B2 account authorization information locally.

Quickstart

This quickstart demonstrates how to initialize the `B2Api` client, authorize with your Backblaze B2 credentials (retrieved from environment variables for security), and then list your B2 buckets. This is a common first step for any interaction with B2 Cloud Storage.

import os
from b2sdk.v3 import B2Api
from b2sdk.v3.account_info.sqlite_account_info import SqliteAccountInfo

# It's recommended to store credentials in environment variables
APPLICATION_KEY_ID = os.environ.get('B2_APPLICATION_KEY_ID', 'YOUR_KEY_ID')
APPLICATION_KEY = os.environ.get('B2_APPLICATION_KEY', 'YOUR_KEY')

if APPLICATION_KEY_ID == 'YOUR_KEY_ID' or APPLICATION_KEY == 'YOUR_KEY':
    print("Please set B2_APPLICATION_KEY_ID and B2_APPLICATION_KEY environment variables.")
else:
    try:
        # Initialize account info storage (can be SqliteAccountInfo, InMemoryAccountInfo, etc.)
        info = SqliteAccountInfo()
        b2_api = B2Api(info)

        # Authorize with Backblaze B2
        b2_api.authorize_account(
            realm='production',  # Or 'test' for integration testing
            application_key_id=APPLICATION_KEY_ID,
            application_key=APPLICATION_KEY
        )
        print("Successfully authorized with Backblaze B2.")

        # Example: List your buckets
        print("\nListing buckets:")
        buckets = b2_api.list_buckets()
        if buckets:
            for bucket in buckets:
                print(f"  - {bucket.name} (ID: {bucket.id_}, Type: {bucket.bucket_type})")
        else:
            print("  No buckets found.")

    except Exception as e:
        print(f"An error occurred: {e}")

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