Azure Storage Blob ChangeFeed client library for Python¶
This preview package for Python enables users to get blob change feed events. These events can be lazily generated, iterated by page, retrieved for a specific time interval, or iterated from a specific continuation token.
Source code | Package (PyPi) | API reference documentation | Product documentation | Samples
Getting started¶
Prerequisites¶
Python 2.7, or 3.5 or later is required to use this package.
You must have an Azure subscription and an Azure storage account to use this package.
Install the package¶
Install the Azure Storage Blob ChangeFeed client library for Python with pip:
pip install azure-storage-blob-changefeed --pre
Create a storage account¶
If you wish to create a new storage account, you can use the Azure Portal, Azure PowerShell, or Azure CLI:
# Create a new resource group to hold the storage account -
# if using an existing resource group, skip this step
az group create --name my-resource-group --location westus2
# Create the storage account
az storage account create -n my-storage-account-name -g my-resource-group
To enable changefeed you can use: Azure Portal, Azure PowerShell or Template.
Authenticate the client¶
Interaction with Blob ChangeFeed client starts with an instance of the ChangeFeedClient class. You need an existing storage account, its URL, and a credential to instantiate the client object.
Get credentials¶
To authenticate the client you have a few options:
Use a SAS token string
Use an account shared access key
Use a token credential from azure.identity
Alternatively, you can authenticate with a storage connection string using the from_connection_string
method. See example: Client creation with a connection string.
You can omit the credential if your account URL already has a SAS token.
Create client¶
Once you have your account URL and credentials ready, you can create the ChangeFeedClient:
from azure.storage.blob.changefeed import ChangeFeedClient
service = ChangeFeedClient(account_url="https://<my-storage-account-name>.blob.core.windows.net/", credential=credential)
Key concepts¶
The Blob ChangeFeed SDK provides one client:
ChangeFeedClient: this client allows you to get change feed events by page, get all change feed events, get events in a time range, start listing events with a continuation token.
Examples¶
The following sections provide several code snippets covering some of the most common Storage Blob ChangeFeed, including:
Client creation with a connection string¶
Create the ChangeFeedClient using the connection string to your Azure Storage account.
from azure.storage.blob.changefeed import ChangeFeedClient
service = ChangeFeedClient.from_connection_string(conn_str="my_connection_string")
Enumerating Events Within a Time Range¶
List all events within a time range.
from datetime import datetime
from azure.storage.blob.changefeed import ChangeFeedClient
cf_client = ChangeFeedClient("https://{}.blob.core.windows.net".format("YOUR_ACCOUNT_NAME"),
credential="Your_ACCOUNT_KEY")
start_time = datetime(2020, 1, 6)
end_time = datetime(2020, 3, 4)
change_feed = cf_client.list_changes(start_time=start_time, end_time=end_time)
# print range of events
for event in change_feed:
print(event)
Enumerating All Events¶
List all events.
from azure.storage.blob.changefeed import ChangeFeedClient
cf_client = ChangeFeedClient("https://{}.blob.core.windows.net".format("YOUR_ACCOUNT_NAME"),
credential="Your_ACCOUNT_KEY")
change_feed = cf_client.list_changes()
# print all events
for event in change_feed:
print(event)
Enumerating Events by Page¶
List events by page.
from azure.storage.blob.changefeed import ChangeFeedClient
cf_client = ChangeFeedClient("https://{}.blob.core.windows.net".format("YOUR_ACCOUNT_NAME"),
credential="Your_ACCOUNT_KEY")
change_feed = cf_client.list_changes().by_page()
# print first page of events
change_feed_page1 = next(change_feed)
for event in change_feed_page1:
print(event)
Troubleshooting¶
Logging¶
This library uses the standard logging library for logging. Basic information about HTTP sessions (URLs, headers, etc.) is logged at INFO level.
Detailed DEBUG level logging, including request/response bodies and unredacted
headers, can be enabled on a client with the logging_enable
argument:
import sys
import logging
from azure.storage.blob.changefeed import ChangeFeedClient
# Create a logger for the 'azure.storage.blob.changefeed' SDK
logger = logging.getLogger('azure.storage')
logger.setLevel(logging.DEBUG)
# Configure a console output
handler = logging.StreamHandler(stream=sys.stdout)
logger.addHandler(handler)
# This client will log detailed information about its HTTP sessions, at DEBUG level
service_client = ChangeFeedClient.from_connection_string("your_connection_string", logging_enable=True)
Next steps¶
More sample code¶
Get started with our Azure Blob ChangeFeed samples.
Several Storage Blob ChangeFeed Python SDK samples are available to you in the SDK’s GitHub repository. These samples provide example code for additional scenarios commonly encountered while working with Blob ChangeFeed:
change_feed_samples.py - Examples for authenticating and operating on the client:
list events by page
list all events
list events in a time range
list events starting from a continuation token
Contributing¶
This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.
When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.
This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.