CHANGELOG.md

Splunk Enterprise SDK for Python Changelog

Version 2.1.1

Changes

• #623 Additional logging in Custom Search Commands
• #622 Check if developer added custom map method in reporting command
• Code reformatting and linting, improvements to GitHub Actions

Version 2.1.0

Changes

• #516 Added support for macros
• Remove deprecated wrap_socket in Context class.
• Added explicit support for self signed certificates in https
• Enforce minimal required tls version in https connection
• Add support for python 3.13
• #559 Add exception logging

Version 2.0.2

Minor changes

• Added six.py file back

Version 2.0.1

Bug fixes

• #567 Moved "deprecation" dependency

Version 2.0.0

Feature updates

• ensure_binary, ensure_str and assert_regex utility methods have been migrated from six.py to splunklib/utils.py

Major changes

• Removed code specific to Python 2
• Removed six.py dependency
• Removed __future__ imports
• Refactored and Updated splunklib and tests to utilize Python 3 features
• Updated CI test matrix to run with Python versions - 3.7 and 3.9
• Refactored Code throwing deprecation warnings
• Refactored Code violating Pylint rules

Bug fixes

• #527 Added check for user roles
• Fix to access the metadata "finished" field in search commands using the v2 protocol
• Fix for error messages about ChunkedExternProcessor in splunkd.log for Custom Search Commands

Version 1.7.4

Bug fixes

• #532 Update encoding errors mode to 'replace' [issue#505]
• #507 Masked sensitive data in logs [issue#506]

Minor changes

• #530 Update GitHub CI build status in README and removed RTD(Read The Docs) reference

Version 1.7.3

Bug fixes

• #493 Fixed file permission for event_writer.py file [issue#487]
• #500 Replaced index_field with accelerated_field for kvstore [issue#497]
• #502 Updated check for IPv6 addresses

Minor changes

• #490 Added ACL properties update feature
• #495 Added Splunk 8.1 in GitHub Actions Matrix
• #485 Added test case for cookie persistence
• #503 README updates on accessing "service" instance in CSC and ModularInput apps
• #504 Updated authentication token names in docs to reduce confusion
• #494 Reuse splunklib.version in handler.request

Version 1.7.2

Minor changes

• #482 Special handling related to the semantic versioning of specific Search APIs functional in Splunk Enterprise 9.0.2 and (Splunk Cloud 9.0.2209). These SDK changes will enable seamless transition between the APIs based on the version of the Splunk Enterprise in use

Version 1.7.1

Bug fixes

• #471 Fixed support of Load Balancer "sticky sessions" (persistent cookies) [issue#438]

Minor changes

• #466 Tests for CSC apps
• #467 Added kwargs parameter for Saved Search History function
• #475 README updates

Version 1.7.0

New features and APIs

• #468 SDK Support for splunkd search API changes

Bug fixes

• #464 Updated checks for wildcards in StoragePasswords [issue#458]

Minor changes

• #463 Preserve third-party cookies

Version 1.6.20

New features and APIs

• #442 Optional retries feature added
• #447 Create job support for "output_mode:json" [issue#285]

Bug fixes

• #449 Set cookie [issue#438]
• #460 Remove restart from client.Entity.disable

Minor changes

• #444 Update tox.ini
• #446 Release workflow refactor
• #448 Documentation changes
• #450 Removed examples and it's references from the SDK

Version 1.6.19

New features and APIs

• #441 JSONResultsReader added and deprecated ResultsReader
  • Pre-requisite: Query parameter 'output_mode' must be set to 'json'
  • Improves performance by approx ~80-90%
  • ResultsReader is deprecated and will be removed in future releases (NOTE: Please migrate to JSONResultsReader)
• #437 Added setup_logging() method in splunklib for logging
• #426 Added new github_commit modular input example
• #392 Break out search argument to option parsing for v2 custom search commands
• #384 Added Float parameter validator for custom search commands
• #371 Modinput preserve 'app' context

Bug fixes

• #439 Modified POST method debug log to not log sensitive body/data
• #431 Add distsearch.conf to Stream Search Command examples [ issue#418 ]
• #419 Hec endpoint issue[ issue#345 ]
• #416 Removed strip() method in load_value() method from data.py file [ issue#400 ]
• #148 Identical entity names will cause an infinite loop

Minor changes

• #440 Github release workflow modified to generate docs
• #430 Fix indentation in README
• #429 Documented how to access modular input metadata
• #427 Replace .splunkrc with .env file in test and examples
• #424 Float validator test fix
• #423 Python 3 compatibility for ResponseReader.str()
• #422 ordereddict and all its reference removed
• #421 Update README.md
• #387 Update filter.py
• #331 Fix a couple of warnings spotted when running python 2.7 tests
• #330 client: use six.string_types instead of basestring
• #329 client: remove outdated comment in Index.submit
• #262 Properly add parameters to request based on the method of the request
• #237 Don't output close tags if you haven't written a start tag
• #149 "handlers" stanza missing in examples/searchcommands_template/default/logging.conf

Version 1.6.18

Bug fixes

• #405 Fix searchcommands_app example
• #406 Fix mod inputs examples
• #407 Fixed issue with Streaming and Generating Custom Search Commands dropping fields that aren't present in the first row of results. More details on how to opt-in to this fix can be found here: https://github.com/splunk/splunk-sdk-python/blob/develop/README.md#customization [ issue#401 ]

Minor changes

• #408 Add search mode example
• #409 Add Support for authorization tokens read from .splunkrc [ issue#388 ]
• #413 Default kvstore owner to nobody [ issue#231 ]

Version 1.6.17

Bug fixes

• #383 Implemented the possibility to provide a SSLContext object to the connect method
• #396 Updated KVStore Methods to support dictionaries
• #397 Added code changes for encoding '/' in _key parameter in kvstore.data APIs.
• #398 Added dictionary support for KVStore "query" methods.
• #402 Fixed regression introduced in 1.6.15 to once again allow processing of empty input records in custom search commands (fix #376)
• #404 Fixed test case failure for 8.0 and latest(8.2.x) splunk version

Minor changes

• #381 Updated current year in conf.py
• #389 Fixed few typos
• #391 Fixed spelling error in client.py
• #393 Updated development status past 3
• #394 Updated Readme steps to run examples
• #395 Updated random_number.py
• #399 Moved CI tests to GitHub Actions
• #403 Removed usage of Easy_install to install SDK

Version 1.6.16

Bug fixes

#312 Fix issue #309, avoid catastrophic backtracking in searchcommands

Version 1.6.15

Bug fixes

• #301 Fix chunk synchronization
• #327 Rename and cleanup follow-up for chunk synchronization
• #352 Allow supplying of a key-value body when calling Context.post()

Minor changes

• #350 Initial end-to-end tests for streaming, reporting, generating custom search commands
• #348 Update copyright years to 2020
• #346 Readme updates to urls, terminology, and formatting
• #317 Fix deprecation warnings

Version 1.6.14

Bug fix

• SearchCommand now correctly supports multibyte characters in Python 3.

Version 1.6.13

Bug fix

• Fixed regression in mod inputs which resulted in error ’file' object has no attribute 'readable’, by not forcing to text/bytes in mod inputs event writer any longer.

Minor changes

• Minor updates to the splunklib search commands to support Python 3

Version 1.6.12

New features and APIs

• Added Bearer token support using Splunk Token in v7.3
• Made modinput text consistent

Bug fixes

• Changed permissions from 755 to 644 for Python files to pass AppInspect checks
• Removed version check on ssl verify toggle

Version 1.6.11

Bug Fix

• Fix custom search command V2 failures on Windows for Python 3

Version 1.6.10

Bug Fix

• Fix long type gets wrong values on Windows for Python 2

Version 1.6.9

Bug Fix

• Fix buffered input in Python 3

Version 1.6.8

Bug Fix

• Fix custom search command on Python 3 on Windows

Version 1.6.7

Changes

• Updated the Splunk Enterprise SDK for Python to work with the Python 3 version of Splunk Enterprise on Windows
• Improved the performance of deleting/updating an input
• Added logging to custom search commands app to showcase how to do logging in custom search commands by using the Splunk Enterprise SDK for Python

Version 1.6.6

Bug fixes

• Fix ssl verify to require certs when true

Minor changes

• Make the explorer example compatible w/ Python 3
• Add full support for unicode in SearchCommands
• Add return code for invalid_args block

Version 1.6.5

Bug fixes

• Fixed XML responses to not throw errors for unicode characters.

Version 1.6.4

New features and APIs

Not Applicable

Minor Changes

• Changed splunklib/binding.py Context class' constructor initialization to support default settings for encrypted http communication when creating the HttpLib object that it depends on. This is extracted from the keyword dictionary that is provided for its initialization. Encryption defaults to enabled if not specified.
• Changed splunklib/binding.py HttpLib class constructor to include the verify parameter in order to support default encryption if the default handler is being used. Encryption defaults to enabled if not specified.
• Changed splunklib/binding.py handler function to include the verify parameter in order to support default encryption.
• Changed splunklib/binding.py handler's nested connect function to create the context in as unverified if specified by the verify parameter.

Bug fixes

Not Applicable

Documentation

• Changed examples/searchcommands_app/package/bin/filter.py FilterCommand.update doc-string from map to update in order to align with Splunk search changes.
• Changed examples/searchcommands_app/package/default/searchbnf.conf [filter-command].example1 from the map keyword to the update keyword in order to align with Splunk search changes.
• Changed splunklib/binding.py Context class' doc-string to include the verify parameter and type information related to the new keyword dictionary parameter verify.
• Changed splunklib/binding.py handler function's doc-string to include the verify parameter and type information related to the parameter verify.
• Changed splunklib/client.py connect function doc-string to include the verify parameter and type information related to the new keyword dictionary parameter verify.
• Changed splunklib/client.py Service Class' doc-string to include the verify parameter and type information related to the new keyword dictionary parameter verify.

Version 1.6.3

New features and APIs

• Support for Python 3.x has been added for external integrations with the Splunk platform. However, because Splunk Enterprise 7+ still includes Python 2.7.x, any apps or scripts that run on the Splunk platform must continue to be written for Python 2.7.x.

Bug fixes

The following bugs have been fixed:

• Search commands error - ERROR ChunkedExternProcessor - Invalid custom search command type: eventing.

• Search commands running more than once for certain cases.

• Search command protocol v2 inverting the distributed configuration flag.

Version 1.6.2

Minor changes

• Use relative imports throughout the SDK.

• Performance improvement when constructing Input entity paths.

Version 1.6.1

Bug Fixes

• Fixed Search Commands exiting if the external process returns a zero status code (Windows only).

• Fixed Search Command Protocol v2 not parsing the maxresultrows and command metadata properties.

• Fixed double prepending the Splunk prefix for authentication tokens.

• Fixed Index.submit() for namespaced Service instances.

• Fixed uncaught AttributeError when accessing Entity properties (GitHub issue #131).

Minor Changes

• Fixed broken tests due to expired SSL certificate.

Version 1.6.0

New Features and APIs

• Added support for KV Store.

• Added support for HTTP basic authentication (GitHub issue #117).

• Improve support for HTTP keep-alive connections (GitHub issue #122).

Bug Fixes

• Fixed Python 2.6 compatibility (GitHub issue #141).

• Fixed appending restrictToHost to UDP inputs (GitHub issue #128).

Minor Changes

• Added support for Travis CI.

• Updated the default test runner.

• Removed shortened links from documentation and comments.

Version 1.5.0

New features and APIs

• Added support for the new experimental Search Command Protocol v2, for Splunk 6.3+.

  Opt-in by setting chunked = true in commands.conf. See examples/searchcommands_app/package/default/commands-scpv2.conf.

• Added support for invoking external search command processes.

  See examples/searchcommands_app/package/bin/pypygeneratext.py.

• Added a new search command type: EventingCommand is the base class for commands that filter events arriving at a search head from one or more search peers.

  See examples/searchcommands_app/package/bin/filter.py.

• Added splunklib logger so that command loggers can be configured independently of the splunklib.searchcommands module.

  See examples/searchcommands_app/package/default/logger.conf for guidance on logging configuration.

• Added splunklib.searchcommands.validators.Match class for verifying that an option value matches a regular expression pattern.

Bug fixes

• GitHub issue 88: splunklib.modularinput, <done/> written even when done=False.

• GitHub issue 115: splunklib.searchcommands.splunk_csv.dict_reader raises KeyError when supports_multivalues = True.

• GitHub issue 119: None returned in _load_atom_entries.

• Various other bug fixes/improvements for Search Command Protocol v1.

• Various bug fixes/improvements to the full splunklib test suite.

Version 1.4.0

New features and APIs

• Added support for cookie-based authentication, for Splunk 6.2+.

• Added support for installing as a Python egg.

• Added a convenience Service.job() method to get a Job by its sid.

Bug fixes

• Restored support for Python 2.6 (GitHub issues #96 & #114).

• Fix SearchCommands decorators and Validator classes (GitHub issue #113).

• Fix SearchCommands bug iterating over None in dict_reader.fieldnames (GitHub issue #110).

• Fixed JSON parsing errors (GitHub issue #100).

• Retain the type property when parsing Atom feeds (GitHub issue #92).

• Update non-namespaced server paths with a /services/ prefix. Fixes a bug where setting the owner and/or app on a Service could produce 403 errors on some REST API endpoints.

• Modular input Argument.title is now written correctly.

• Client.connect will now always return a Service instance, even if user credentials are invalid.

• Update the saved_search/saved_search.py example to handle saved searches with names containing characters that must be URL encoded (ex: "Top 5 sourcetypes").

Minor Changes

• Update modular input examples with readable titles.

• Improvements to splunklib.searchcommands tests.

• Various docstring and code style corrections.

• Updated some tests to pass on Splunk 6.2+.

Version 1.3.1

Bug fixes

• Hot fix to binding.py to work with Python 2.7.9, which introduced SSL certificate validation by default as outlined in PEP 476.
• Update async, handler_proxy, and handler_urllib2 examples to work with Python 2.7.9 by disabling SSL certificate validation by default.

Version 1.3.0

New features and APIs

• Added support for Storage Passwords.

• Added a script (GenerateHelloCommand) to the searchcommand_app to generate a custom search command.

• Added a human-readable argument titles to modular input examples.

• Renamed the searchcommand csv module to splunk_csv.

Bug fixes

• Now entities that contain slashes in their name can be created, accessed and deleted correctly.

• Fixed a performance issue with connecting to Splunk on Windows.

• Improved the service.restart() function.

Version 1.2.3

New features and APIs

• Improved error handling in custom search commands

  SearchCommand.process now catches all exceptions and

  1. Writes an error message for display in the Splunk UI.

     The error message is the text of the exception. This is new behavior.

  2. Logs a traceback to SearchCommand.logger. This is old behavior.

• Made ResponseReader more stream-like, so that it can be wrapped in an io.BufferedReader to realize a significant performance gain.

  Example usage

  import io
  ...
  response = job.results(count=maxRecords, offset=self._offset)
  resultsList = results.ResultsReader(io.BufferedReader(response))
  

Bug fixes

1. The results reader now catches SyntaxError exceptions instead of xml.etree.ElementTree.ParseError exceptions. ParseError wasn't introduced until Python 2.7. This masked the root cause of errors data errors in result elements.

2. When writing a ReportingCommand you no longer need to include a map method.

Version 1.2.2

Bug fixes

1. Addressed a problem with autologin and added test coverage for the use case.

   See ServiceTestCase.test_autologin in tests/test_service.py.

Version 1.2.1

New features and APIs

• Added features for building custom search commands in Python

  1. Access Splunk Search Results Info.

     See the SearchCommand.search_results_info property.

  2. Communicate with Splunk.

     See the SearchCommand.service property.

  3. Control logging and view command configuration settings from the Splunk command line

     • The logging_configuration option lets you pick an alternative logging configuration file for a command invocation.

     • The logging_level option lets you set the logging level for a command invocation.

     • The show_configuration option writes command configuration settings to the Splunk Job Inspector.

  4. Get a more complete picture of what's happening when an error occurs

     Command error messages now include a full stack trace.

  5. Enable the Splunk Search Assistant to display command help.

     See examples/searchcommands_app/default/searchbnf.conf

  6. Write messages for display by the job inspector.

     See SearchCommand.messages.

• Added a feature for building modular inputs.

  1. Communicate with Splunk.

     See the Script.service property.

Bug fixes

• When running setup.py dist without running setup.py build, there is no longer a No such file or directory error on the command line, and the command behaves as expected.

• When setting the sourcetype of a modular input event, events are indexed properly.

  Previously Splunk would encounter an error and skip them.

Quality improvements

• Better code documentation and unit test coverage.

Version 1.2

New features and APIs

• Added support for building custom search commands in Python using the Splunk SDK for Python.

Bug fix

• When running setup.py dist without running setup.py build, there is no longer a No such file or directory error on the command line, and the command behaves as expected.

• When setting the sourcetype of a modular input event, events are indexed properly. Previously Splunk would encounter an error and skip them.

Breaking changes

• If modular inputs were not being indexed by Splunk because a sourcetype was set (and the SDK was not handling them correctly), they will be indexed upon updating to this version of the SDK.

Minor changes

• Docstring corrections in the modular input examples.

• A minor docstring correction in splunklib/modularinput/event_writer.py.

Version 1.1

New features and APIs

• Added support for building modular input scripts in Python using the Splunk SDK for Python.

Minor additions

• Added 2 modular input examples: Github forks and random numbers.

• Added a dist command to setup.py. Running setup.py dist will generate 2 .spl files for the new modular input example apps.

• client.py in the splunklib module will now restart Splunk via an HTTP post request instead of an HTTP get request.

• .gitignore has been updated to ignore local and metadata subdirectories for any examples.

Version 1.0

New features and APIs

• An AuthenticationError exception has been added. This exception is a subclass of HTTPError, so existing code that expects HTTP 401 (Unauthorized) will continue to work.

• An "autologin" argument has been added to the splunklib.client.connect and splunklib.binding.connect functions. When set to true, Splunk automatically tries to log in again if the session terminates.

• The is_ready and is_done methods have been added to the Job class to improve the verification of a job's completion status.

• Modular inputs have been added (requires Splunk 5.0+).

• The Jobs.export method has been added, enabling you to run export searches.

• The Service.restart method now takes a "timeout" argument. If a timeout period is specified, the function blocks until splunkd has restarted or the timeout period has passed. Otherwise, if a timeout period has not been specified, the function returns immediately and you must check whether splunkd has restarted yourself.

• The Collections.__getitem__ method can fetch items from collections with an explicit namespace. This example shows how to retrieve a saved search for a specific namespace:

    from splunklib.binding import namespace
    ns = client.namespace(owner='nobody', app='search')
    result = service.saved_searches['Top five sourcetypes', ns]
  

• The SavedSearch class has been extended by adding the following:

  • Properties: alert_count, fired_alerts, scheduled_times, suppressed
  • Methods: suppress, unsuppress

• The Index.attached_socket method has been added. This method can be used inside a with block to submit multiple events to an index, which is a more idiomatic style than using the existing Index.attach method.

• The Indexes.get_default method has been added for returning the name of the default index.

• The Service.search method has been added as a shortcut for creating a search job.

• The User.role_entities convenience method has been added for returning a list of role entities of a user.

• The Role class has been added, including the grant and revoke convenience methods for adding and removing capabilities from a role.

• The Application.package and Application.updateInfo methods have been added.

Breaking changes

• Job objects are no longer guaranteed to be ready for querying. Client code should call the Job.is_ready method to determine when it is safe to access properties on the job.

• The Jobs.create method can no longer be used to create a oneshot search (with "exec_mode=oneshot"). Use the Jobs.oneshot method instead.

• The ResultsReader interface has changed completely, including:

  • The read method has been removed and you must iterate over the ResultsReader object directly.
  • Results from the iteration are either dicts or instances of results.Message.

• All contains methods on collections have been removed. Use Python's in operator instead. For example:

    # correct usage
    'search' in service.apps
  
    # incorrect usage
    service.apps.contains('search')
  

• The Collections.__getitem__ method throws AmbiguousReferenceException if there are multiple entities that have the specified entity name in the current namespace.

• The order of arguments in the Inputs.create method has changed. The name argument is now first, to be consistent with all other collections and all other operations on Inputs.

• The ConfFile class has been renamed to ConfigurationFile.

• The Confs class has been renamed to Configurations.

• Namespace handling has changed and any code that depends on namespace handling in detail may break.

• Calling the Job.cancel method on a job that has already been cancelled no longer has any effect.

• The Stanza.submit method now takes a dict instead of a raw string.

Bug fixes and miscellaneous changes

• Collection listings are optionally paginated.

• Connecting with a pre-existing session token works whether the token begins with 'Splunk ' or not; the SDK handles either case correctly.

• Documentation has been improved and expanded.

• Many small bugs have been fixed.

0.8.0 (beta)

Features

• Improvements to entity state management
• Improvements to usability of entity collections
• Support for collection paging - collections now support the paging arguments: count, offset, search, sort_dir, sort_key and sort_mode. Note that Inputs and Jobs are not pageable collections and only support basic enumeration and iteration.
• Support for event types:
  • Added Service.event_types + units
  • Added examples/event_types.py
• Support for fired alerts:
  • Added Service.fired_alerts + units
  • Added examples/fired_alerts.py
• Support for saved searches:
  • Added Service.saved_searches + units
  • Added examples/saved_searches.py
• Sphinx based SDK docs and improved source code docstrings.
• Support for IPv6 - it is now possible to connect to a Splunk instance listening on an IPv6 address.

Breaking changes

Module name

The core module was renamed from splunk to splunklib. The Splunk product ships with an internal Python module named splunk and the name conflict with the SDK prevented installing the SDK into Splunk Python sandbox for use by Splunk extensions. This module name change enables the Python SDK to be installed on the Splunk server.

State caching

The client module was modified to enable Entity state caching which required changes to the Entity interface and changes to the typical usage pattern.

Previously, entity state values where retrieved with a call to Entity.read which would issue a round-trip to the server and return a dictionary of values corresponding to the entity content field and, in a similar way, a call to Entity.readmeta would issue in a round-trip and return a dictionary containing entity metadata values.

With the change to enable state caching, the entity is instantiated with a copy of its entire state record, which can be accessed using a variety of properties:

• Entity.state returns the entire state record
• Entity.content returns the content field of the state record
• Entity.access returns entity access metadata
• Entity.fields returns entity content metadata

Entity.refresh is a new method that issues a round-trip to the server and updates the local, cached state record.

Entity.read still exists but has been changed slightly to return the entire state record and not just the content field. Note that read does not update the cached state record. The read method is basically a thin wrapper over the corresponding HTTP GET that returns a parsed entity state record instead of the raw HTTP response.

The entity callable returns the content field as before, but now returns the value from the local state cache instead of issuing a round-trip as it did before.

It is important to note that refreshing the local state cache is always explicit and always requires a call to Entity.refresh. So, for example if you call Entity.update and then attempt to retrieve local values, you will not see the newly updated values, you will see the previously cached values. The interface is designed to give the caller complete control of when round-trips are issued and enable multiple updates to be made before refreshing the entity.

The update and action methods are all designed to support a fluent style of programming, so for example you can write:

entity.update(attr=value).refresh()

And

entity.disable().refresh()

An important benefit and one of the primary motivations for this change is that iterating a collection of entities now results in a single round-trip to the server, because every entity collection member is initialized with the result of the initial GET on the collection resource instead of requiring N+1 round-trips (one for each entity + one for the collection), which was the case in the previous model. This is a significant improvement for many common scenarios.

Collections

The Collection interface was changed so that Collection.list and the corresponding collection callable return a list of member Entity objects instead of a list of member entity names. This change was a result of user feedback indicating that people expected to see eg: service.apps() return a list of apps and not a list of app names.

Naming context

Previously the binding context (binding.Context) and all tests & samples took a single (optional) namespace argument that specified both the app and owner names to use for the binding context. However, the underlying Splunk REST API takes these as separate app and owner arguments and it turned out to be more convenient to reflect these arguments directly in the SDK, so the binding context (and all samples & test) now take separate (and optional) app and owner arguments instead of the prior namespace argument.

You can find a detailed description of Splunk namespaces in the Splunk REST API reference under the section on accessing Splunk resources at:

• http://docs.splunk.com/Documentation/Splunk/latest/RESTAPI/RESTresources

Misc. API

• Update all classes in the core library modules to use new-style classes
• Rename Job.setpriority to Job.set_priority
• Rename Job.setttl to Job.set_ttl

Bug fixes

• Fix for GitHub Issues: 2, 10, 12, 15, 17, 18, 21
• Fix for incorrect handling of mixed case new user names (need to account for fact that Splunk automatically lowercases)
• Fix for Service.settings so that updates get sent to the correct endpoint
• Check name arg passed to Collection.create and raise ValueError if not a basestring
• Fix handling of resource names that are not valid URL segments by quoting the resource name when constructing its path

0.1.0a (preview)

• Fix a bug in the dashboard example
• Ramp up README with more info

0.1.0 (preview)

• Initial Python SDK release