Tornado Async Await Example

1 documentation,网上大部分教程都不适合新版(5. And async context managers like transaction() etc, are only possible in Python 3. This is much more concise and takes away all the confusion there was to the difference between ‘yield’ and ‘yield from’. For example in Python, the two most famous approaches are the usage of Tornado Web Server and the built-in library asyncio. Jul 07, 2018 · Tinker and play around with source code, that's the programmer's way of life. jsonrpcserver Examples from aiohttp import web from jsonrpcserver import method, async_dispatch as dispatch from tornado import ioloop, web from jsonrpcserver. 经过几天的寻找,发现些异步查询mysql的库,比如 tornado-mysql, aiomysql等, 有些还是实验性质的,且大多数不成熟,不支持ORM(如sqlalchemy),只有aiomysql支持sqlalchemy,文档还不够详细。. js and friends) is to use non-blocking APIs and bind callbacks to asynchronous events. Element will make it be rendered, with the result sent as the response body:. Drop resolve param from TCPConnector. The Task asynchronous programming model (TAP) provides an abstraction over asynchronous code. For example, tornado. I wanted to something fast and async, so I would normally use Go, but it's an interface to a python project, so I had to find a good asynchronous python web server. The following examples assume that you are already familiar with asyncio, coroutines, and the event loop. Terminology: - *native coroutine* term is used for "async def" functions. Here’s an example of sending a desktop notification, using blocking I/O:. TextMate used to do single keystroke undo which was infuriating when going back through a large edit history, addressing this appears to have paralyzed development and sidelined what had been the darling text editor of the hipter screencast brogrammer crowd), handle errors, and so on. In addition to solving the C10k issue (which simply means to handle 10k connections at any given time), the asynchronous framework uses a non-blocking network I/O. You don't generally need to use "gen. 5 and why it is awesome Speaker(s) Yury Selivanov The talk will start with a brief coverage of the story of asynchronous programming in Python - Twisted, Tornado, Stackless Python & greenlets, eventlet, Tornado, asyncio & curio. For example:. Then I'll go over asyncio and curio, showing async/await by example, explaining that in reality it's a very easy to use language feature. 3,你可以用它们代替 yield 为基础的协程. All visible side effects are synchronized between the call to async and the call to fn, and between its return point and the access to the returned future's share state. Oct 30, 2016 · It wasn't as simple in Python 3. Find a callback-based equivalent. For example, Tornado is specifically targeted at web application programming whereas Gevent and Twisted are more general concurrency libraries for interleaving non-blocking 'threads'. And here are some general notes: Be aware of current asyncio event loop!. A blocking HTTP client. 3 开始, 在协程基础上你可以使用这些来代替 yield. 建议Tornado初学者直接学习Tornado官网的文档:Tornado Web Server - Tornado 5. Should I stick with asyncio, or return to gevent? I spent a few days to learn basics of asyncio. Source code for distributed. 从 Tornado 4. Lock from tornado. And, because Tornado supports the await protocols you can also use the existing shadow concurrency API (everything prepended with an underscore) with await. Gevent relies on greenlets for an implicit event loop and monkey patches the standard library to support it's evented operation. A discussion of the pros and cons of using asynchronous frameworks for web development in the Python ecosystem. gen — Simplify asynchronous code¶ tornado. If the DB you're using has asychronous Python bindings (ideally ones geared for Tornado specifically, like Motor for MongoDB or momoko for Postgres), then you'll be able to run your DB queries without blocking the server; no separate processes or threads needed. Motor presents a coroutine-based API for non-blocking access to MongoDB from Tornado or asyncio. You may be thinking with dread, "Concurrency, parallelism, threading, multiprocessing. https:github. 3, 你可以用它们代替 yield 为基础的协程. ProactorEventLoop() asyncio. Tornado Example: Delegating an blocking task to a worker thread pool from an asynchronous request handler - gist:2185380 Skip to content All gists Back to GitHub. Real World Async and Await Code Example I have been looking everywhere to find good real world examples of the new Async and Await features in. Asynchronous HTTP Requests in Python 3. I am using Twisted, Tornado, gevent etc. Asynchronous Clients. It uses the async/await syntax introduced in PEP 492, and is therefore Python 3. Last two items are a huge advantage of threads approach. Similar to the first option, callback-based libraries are available for many tasks, although they are slightly more complicated to use than a library designed for coroutines. async/await is really an API for asynchronous programming: People shouldn't think that async/await as synonymous with asyncio, but instead think that asyncio is a framework that can utilize the async/await API for asynchronous programming. Asynchronous HTTP Requests in Python 3. HTTPRequest(). You can either: Add tornado_async_transformer. It provides a new, streamlined syntax for asynchronous development. In addition to solving the C10k issue (which simply means to handle 10k connections at any given time), the asynchronous framework uses a non-blocking network I/O. HTTPClient (async_client_class: Type[AsyncHTTPClient] = None, **kwargs) [source] ¶. Asynchronous programming with Tornado. That, plus the fact that the async/await (or future/promise) idea has proven itself to be effective and useful in other languages, suggests that Python needs additional constructions for doing coroutines. call_soon_threadsafe is different from call_soon when the loop *is* running. In the last months I had occasion to use Azure Storage as primary persistence layer for a document management system for my employer, William Demant Holding. Tornado框架 简介: Tornado是使用Python编写的一个强大的. A callback is a function, and it means “Once this is done, execute this function”. The first problem is not specific to Scrapy; it is the same if you're using inlineCallbacks from twisted, tornado. 从 Tornado 4. JSONRPCRequest with the attributes method and params (and id and version should they be required). run (main ()). Enter async/await. Tornado文档翻译(三) 书接上回Tornado官方文档截图感觉他这个文档把好多后面的内容拿到简介里面来讲,没有基础的人很难看懂。 先往后翻译着吧。 译文:它是如何工作的这一部分解释装饰协程的操作原理,原始协程从概念上讲基本一致,但是由于与Python运行. 0 前后写法稍有不同,下面对Tornado 请求异步非阻塞作一下总结学习。. http_client. Jan 16, 2019 · Async IO is a concurrent programming design that has received dedicated support in Python, evolving rapidly from Python 3. Tornado is designed to run all your operations in a single thread, but utilize asynchronous I/O to avoid blocking as much as possible. I found example for MongoDB on async mongo example but I couldn't find anything like motor for SQLAlchemy. Server () app = socketio. set_event_loop(), but that is not. coroutine decorator, and await in. Here you can see two new things async and await. It is so confusing! tornado has added support for async/await in version 4. sqlalchemy. asynchronous,tornado,future. Write the contents of this file to a tornado. MotorCursor methods such as to_list() perform actual operations. The loop's thread_id is only set when the loop runs, but the main loop in that example never runs. 5: async and await; How it works; How to call a coroutine; Coroutine patterns. Chances are I just can't see far enough. 5 から async/await (ネイティブコルーチン) が利用可能になった. 从Tornado 4. 这是作者自己翻译的,在我的产品上发布,好像百度目前还搜不到 sanic 相关的中文文档,觉得非常不错,我就顺便帮忙推广下,大家多多支持,也多多支持我的产品. curl_httpclient with a properly-configured build of libcurl). So now anywhere you see the word async, you know the function will run asynchronously. Async and await are a pair of keywords that are introduced by many programming languages. I'm extremely enthusiastic about `async/await` semantics, and in particular async iterators and the `for async` loop. Vibora is a fast, asynchronous and elegant Python 3. 从 Tornado 4. Sadly a few weeks later he left the company, because of personal reasons and a bug appeared in his written service. sleep(), but with more async. The essay that explains why there is a different synchronous ecosystem: Nathaniel J. Curio Example Server¶ This example is a basic HTTP/2 server written using curio, David Beazley’s example of how to build a concurrent networking framework using Python 3. If you have been dabbling in this area, you'd have probably used some of the most popular web frameworks already — Django, Flask, Falcon, Tornado, CherryPy, among others. Event-handling is necessitated by the way human-computer interaction works — you’re talking to the analog world, it’s not going to be pretty. I've not used it though so. slides https://jettify. _gather ( futures ) # asynchronous. run_until_complete(test_example()). Basically it allows you to write asynchronous clients and servers. wait allowed a coroutine to wait for the semaphore to be unlocked without acquiring it. worker import Worker, parse_memory_limit logger = logging. #!/usr/bin/env python """ Pymodbus Asynchronous Client Examples-----The following is an example of how to use the asynchronous modbus client implementation from pymodbus with ayncio. tornado >= 5以上がインストールされたjupyter-notebook上でevent_loopを扱うとRuntimeError: This event loop is already runningになる Python tornado Jupyter asyncio More than 1 year has passed since last update. Python previously had few great options for asynchronous programming. In python you can chose what event loop to hook to async/await, and hence we have gevent, qt, uvloop, twisted, asyncio, tornado, trio and curio as competing implementations. Examples === 4. c#,mongodb,asynchronous,parallel-processing,async-await. PEP 492 -- Coroutines with async and await syntax Class es In order to allow better integration with existing frameworks (such as Tornado, see [13]) and compilers (such as Cython, see [16]), two new Abstract Base Class es (ABC) are added: collections. receive() или async for msg in ws:) так и для записи Вы должны использовать только одну задачу, но асинхронная отправка данных (например ws. https_client Get an asynchronous HTTP client. Event-handling is necessitated by the way human-computer interaction works — you’re talking to the analog world, it’s not going to be pretty. coroutine decorator, and await in place of yield. Trio: a friendly Python library for async concurrency and I/O¶ The Trio project’s goal is to produce a production-quality, permissively licensed , async/await-native I/O library for Python. js), and, object oriented languages will have object inquires, listener patterns, event patterns, etc. 4 was released on March 16th 2014, 3. It is intended for those, who knows nothing about JWT and looks for usage examples. For example in Python, the two most famous approaches are the usage of Tornado Web Server and the built-in library asyncio. Now customize the name of a clipboard to store your clips. The source is on GitHub and the docs are on ReadTheDocs. js and Tornado are both open source tools. 3, you can use them in place of yield-based coroutines. Moving to Task and async/await has likely made most C# developers’ lives easier overall. HTTPRequest(). The talk will start with a brief coverage of the story of asynchronous programming in Python -- Twisted, Tornado, Stackless Python & greenlets, eventlet, Tornado, asyncio & curio. Find a callback-based equivalent. Welcome to Reddit. asynchronous: bool (False by default) Set to True if using this cluster within async/await functions or within Tornado gen. G3log is an asynchronous, "crash safe", logger that is easy to use with default logging sinks or you can add your own. Introducing aiohttp_admin lightning talk Motivation. 5 introduces the async and await keywords (functions using these keywords are also called "native coroutines"). Some tutorials, while great for the developer getting their toes wet, try to illustrate real world examples, but are actually just beefed-up "hello, world"s. Howto do unittest for tornado + async def? My example also works if I replace tornado. Python Tornado Asynchronous Whois Client. This enhances its speed, offering non-blocking capabilities. So you’ve heard that Python now supports that fancy async/await syntax. This is much more concise and takes away all the confusion there was to the difference between ‘yield’ and ‘yield from’. You can control the flow of data through your stream over time. What is Tornado? A Python web framework and asynchronous networking library, originally developed at FriendFeed. 3 开始, 在协程基础上你可以使用这些来代替 yield. 1 documentation案例比较实用。. https_client Get an asynchronous HTTP client. Apr 13, 2018 · The await operator is applied to a task in an asynchronous method to insert a suspension point in the execution of the method until the awaited task completes. call_soon_threadsafe is different from call_soon when the loop *is* running. A libcst transformer for updating tornado @gen. It is also occasionally cumbersome; wrapping a code snippet in some asynchronous processing is messy, for example. Starting with asyncio in python 3. And that’s exactly what we need! The complete working example is provided below. If you want to learn more we strongly recommend reading the Trio Tutorial Primer on async programming. Simply use async def foo() in place of a function definition with the @gen. worker import Worker, parse_memory_limit logger = logging. js, while over 34 developers mention "Open source" as the leading cause for choosing Tornado. Nice! dfs = [await get_table (browser, page_nb) for page_nb in range (0, num_pages)] await browser. You can either: Add tornado_async_transformer. async/await in Python 3. However, if another coroutine received control and ran for 2 seconds, by the time we get back to the first coroutine 2 seconds have already passed. run_until_complete() blocks execution until all calls complete. run_sync(main) In my project many asynchronous inserts and connections count up to ~800. Each being a standalone library they have a certain opinionated approach that is somewhat incompatible with the others. For example, in a coroutine you may want to sleep for 1 second. Why "__aiter__" returns awaitable -----. The Server¶. Just create your own scheduler loop that sleeps and executes any tasks scheduled: import math, time async def scheduler(): while True: # sleep until the next whole second now = time. 5: async and await ¶ Python 3. This should remain False for normal use. for a server, you might import a raw HTTP2 library and go bareback. The example that brought me to this was this — I was. Tornado¶ Tornado is a Python web framework and asynchronous networking library. (Well, OK, you could just not use Trio. 4 and improved further in Python 3. 03/18/2019; 10 minutes to read +12; In this article. A callback is a function, and it means “Once this is done, execute this function”. What is Tornado? A Python web framework and asynchronous networking library, originally developed at FriendFeed. x版本中,这几个装饰器都被标记为deprcated(过时),我们可以通过Python 3. Warnings, await operator. Create the client when your application starts and reuse that one client for the lifetime of the process, as shown in these examples. Instances of class socketio. PostgresqlDatabase ('test') loop = asyncio. The following are code examples for showing how to use tornado. Apr 13, 2018 · The await operator is applied to a task in an asynchronous method to insert a suspension point in the execution of the method until the awaited task completes. 7 Reduced number of servers by 25%. NET Framework. It is so simple: Just create views. 4, but then the async/await keywords became part of the language in Python 3. json_fetch instead of using the result directly. json_fetch instead of using the result directly. In python you can chose what event loop to hook to async/await, and hence we have gevent, qt, uvloop, twisted, asyncio, tornado, trio and curio as competing implementations. Note: code examples below are written for Python 3. savechangesasync. 5 or higher and. Async fixtures need the event loop, and so must have the same or narrower scope than the event_loop fixture. This is much more concise and takes away all the confusion there was to the difference between 'yield' and 'yield from'. Start a tornado HTTP server that listens on all available interfaces. In C#, when you override a method, it is permitted to make the override async when the original method was not. async def f (): client = await Client (asynchronous = True) Operations that used to block now provide Tornado coroutines on which you can await. You can control the flow of data through your stream over time. 5, it's difficult to understand how. In this case, Tornado supports a limited mode of operation, does not support asynchronous operation, but allows a subset of Tornado's functions in WSGI-only environments. Async IO is a concurrent programming design that has received dedicated support in Python, evolving rapidly from Python 3. We add the async keyword before our function declaration. gen is a generator-based interface to make it easier to work in an asynchronous environment. For example, a GUI application would not want the UI to block until all asynchronous transfers are handled – that would defeat the purpose of making them asynchronous. And that's exactly what we need! The complete working example is provided below. Web API is a feature of the ASP. Using multi_cached decorator. The new Async I/O support finally brings first-class support that. Done around 400 miles on it in wealthy suburbs with little memories, definitely an encouraging online society At the same as above Over an 8 attorney ken turner law firm, p Quote from hertz one time on my car Cheap auto insurance liability limits, for example, driver b was driving alone ireland Powerful creating performance at the time at a 10. You can vote up the examples you like or vote down the ones you don't like. Overview of Python-Tornado V4 Storage & Playback with PubNub. 5 から async/await (ネイティブコルーチン) が利用可能になった. Jul 15, 2018 · In python you can chose what event loop to hook to async/await, and hence we have gevent, qt, uvloop, twisted, asyncio, tornado, trio and curio as competing implementations. run_until_complete(test_example()). For a more complete example see the implementation of GridFSHandler. This version is the biggest upgrade yet. js and friends) is to use non-blocking APIs and bind callbacks to asynchronous events. ) I think that resuming a generator asynchronously is always going to be dependent on the event loop. The async keyword (3. Basically it allows you to write asynchronous clients and servers. A callback is a function, and it means “Once this is done, execute this function”. For async-await to make sense you need to await something that can actually run asynchronous/parellel, like io from requests. Async Asyncio Client Example¶. I have 30 instances of Tornado on different servers with connection to single MongoDB instance. 11/14/2017; 15 minutos para ler; Neste artigo. gen ( estoy usando mysql a continuación sqlalchemy, en el momento en que mis controladores de lee de la base de datos y devolver el resultado, me gustaría hacer este async). 简单的通过使用 async def foo() 来代替 @gen. Updates are propagated to all connected clients. 0 and higher, more than 90% of the Twisted unit tests run on Python 3: [Twisted-Python] More tests. Why you might want to write asynchronous code? One can do useful work. The Open Data Protocol (OData) is a data access protocol for the web. An example below shows only an obvious non-asynchronous functionality. 5 version, Python acknowledged the impact of Node. We've come a really long road, and it's important to understand how we ended up with async/await. async / await. Coroutines are the recommended way to write asynchronous code in Tornado. The socket object is kept open until it is closed explicitly to allow callbacks to write to the socket at a later point. The thread will at least guarantee asynchronous execution inside an event loop that you operate. SendAsync(new ArraySegment(messageBuffer, offset, count), WebSocketMessageType. github page pypi page. Pipenev is a packaging and environment tool that python programmers use to create virtual environments for projects while also. Providing HTTP services. Oct 30, 2016 · It wasn't as simple in Python 3. RedisPipe RedisPipe is the high-throughput Go client with implicit pipelining and robust Cluster support. See my response: city: ". This is much more concise and takes away all the confusion there was to the difference between 'yield' and 'yield from'. Smith , Some thoughts on asynchronous API design in a post-async/await world Curio doesn't have much in the way of tooling yet. js javascript 2016-02-18 Python. ) Here’s an example function that uses trio. NET, Python and JavaScript While I am planning to write a review of aiohttp, an event-driven HTTP client/server implementation for Python, I decided to write something about asynchronous programming and the async/await syntax in. for HTTP requests you might use curequests or asks. # 指南 本指南涵盖的 Koa 主题不与 API 直接相关,例如编写中间件的最佳做法和应用程序结构建议。在这些例子中,我们使用 async 函数作为中间件 - 您也可以使用 commonFunction 或 generatorFunction,两者有些许不同。. Here's an example of batching HTTP requests that run concurrently to several servers, while waiting for responses before processing. Starting in Tornado 4. Async in the Python world. For example, the green switch is a heavier blue, and the "clear" (milky) switch is a heavier and more feedbacky brown. Instead I'd recommend checking out aiohttp which is built with that in mind and also maintained by one of the guys behind asyncio. This method is asynchronous and must be called with ``await`` or @tornado. coroutine decorator, and await in place of yield. It supports both WebSocket server and client. Edit on GitHub; Flask-aiohttp — Asynchronous Flask application with aiohttp. peewee-async¶. coroutine 装饰器, 用 await 来代替 yield. AsyncHTTPClient]] = None, **kwargs: Any) [source] ¶ A blocking HTTP client. Two < operationName > Async operations for use with the event-based asynchronous calling approach. Only Tornado version 5 and newer are supported, thanks to its tight integration with asyncio. Nov 11, 2016 · Python added asyncio to the standard library in 3. loop() accepts arguments to set a timeout and to limit the number of times the loop is run. 1 - a Python package on PyPI - Libraries. Aiohttp is an asynchronous web framework which heavily utilizes Python 3. sleep() is like time. PEP 492 -- Coroutines with async and await syntax Class es In order to allow better integration with existing frameworks (such as Tornado, see [13]) and compilers (such as Cython, see [16]), two new Abstract Base Class es (ABC) are added: collections. Mar 15, 2016 · Create a RESTful API with authentication using Web API and Jwt Published on Mar 15, 2016. As long as you declare or decorate the function with async syntax, you can use await or yield from depending on your implementation to call the function. It purportedly can handle thousands of threads (tasklets) in the context of a very parallel game application, but remains pretty single-core. How to make SQLAlchemy in Tornado to be async?I found example for MongoDB on async mongo example but I couldn't find anything like motor for SQLAlchemy. As a PEP 492 author, I'd really like to have a chance to better explain the topic, show why async/await is important and how it will affect Python. Exactly what it returns may vary, though. Tornado¶ Tornado argument parsing is available via the webargs. 5引入了async和await关键字(使用这些关键字的函数也被称为"原生协程"). This method calls flush() on the RequestHandler, so ensure all headers have already been set. 5, but coming from a world of well established tools like [Twisted][2] and [Tornado][3]. asyncio in Python 3. https://code-examples. G3log is made with plain C++14 (C++11 support up to release 1. async def consumer_handler (websocket, path): async for message in websocket: await consumer (message) In this example, consumer represents your business logic for processing messages received on the WebSocket connection. The Task asynchronous programming model (TAP) provides an abstraction over asynchronous code. 4 and up) - single-threaded concurrency. For a more complete example see the implementation of GridFSHandler. Async await usage for MongoDB repository. It became famous with NodeJS but you can find libraries that support it in most major languages. Teppiche Zimmer DDR__5-100 Bett Armband 3 Stück Parure Tris Bettvorleger Vintage Wirkung Seide Gelb. asyncio async/await nsq support - 1. A very common design pattern in asynchronous frameworks (including tornado, twisted, node. ETL Pipelines with Prefect¶. I have now updated the examples to work with the most recent version at the time of this writing 3. Below is a demonstration. SendAsync(new ArraySegment(messageBuffer, offset, count), WebSocketMessageType. #!/usr/bin/env python """ Pymodbus Asynchronous Client Examples-----The following is an example of how to use the asynchronous modbus client implementation from pymodbus with ayncio. This is possible because a is suspended, waiting for b to resolve. Generally, there are three possible explanations for why the async app seems slow: The network has slowed, and it’s taking a long time to get a response from the other server in the transaction. tornadoparser module. none_as_none¶. I’ve tried this js code so far but didn’t work out for me. authenticated async def. In examples folder you can check different use cases: Sanic, Aiohttp and Tornado; Python object in Redis; Custom serializer for compressing data; TimingPlugin and HitMissRatioPlugin demos; Using marshmallow as a serializer; Using cached decorator. For example, here’s a coroutine-based handler:. One such package is aiohttp which is an HTTP client/server for asyncio. The Visual Studio Async CTP will extend Visual Studio 2010. 5 and compatible from Tornado 4. The following are code examples for showing how to use tornado. Among it's features it introduces new syntax focused on facilitating writing asynchronous code - await expression and async def, async with and async forstatements. Toro’s Semaphore. Moving to Task and async/await has likely made most C# developers’ lives easier overall. Simply use async def foo() in place of a function definition with the @gen. async/await is really an API for asynchronous programming: People shouldn't think that async/await as synonymous with asyncio, but instead think that asyncio is a framework that can utilize the async/await API for asynchronous programming. Why asyncio's run_in_executor blocks tornado's get handler? Here is an example how to do it, Python 3. JSONRPCRequest with the attributes method and params (and id and version should they be required). The docs could be improved, but here is an example: [#8088] Support async/await with Deferreds by hawkowl · Pull Request #453 · twisted/twisted. Making async and await proper keywords before 3. Gevent is a coroutine-based Python networking library that uses greenlet to provide a high-level synchronous API on top of libev event loop. TextMate used to do single keystroke undo which was infuriating when going back through a large edit history, addressing this appears to have paralyzed development and sidelined what had been the darling text editor of the hipter screencast brogrammer crowd), handle errors, and so on. These are async and await keywords in Python. 3, but they do not use the standard library, and they do not call asyncio. yield from is gone, use async/await syntax. coroutine, and calls finish for you when the coroutine returns. The socket object is kept open until it is closed explicitly to allow callbacks to write to the socket at a later point. Hi, on my django project, at a point i resize an image with pilow before associating it to django field, then saving the instance. For example, Tornado is specifically targeted at web application programming whereas Gevent and Twisted are more general concurrency libraries for interleaving non-blocking 'threads'. The following functions are in WSGI mode. A few classes and functions were rewritten using async and await for asynchronous code (this syntax was introduced in python 3. It is so confusing! tornado has added support for async/await in version 4. Curio allows you to write low­level network servers almost exactly like you would with threads. Async Asyncio Serial Client Example¶. For today we will do an introduction to the latter, as it has gone through tons of iterations and improvements lately and it is ready to charm people with its intuitive approach. You will also notice that beyond just async, the Python 3. Starting in Tornado 4. Below is a list of examples from aiomysql/examples. user5500750. Execute queries. In this case, Tornado supports a limited mode of operation, does not support asynchronous operation, but allows a subset of Tornado's functions in WSGI-only environments. I will focus on solely on asynchronous programming in Tornado. - *generator-based coroutine* term is used for PEP 380 coroutines used in asyncio. Change the decorator and you should see your print. # Async and Await. NET Framework 4. Drop resolve param from TCPConnector. A discussion of the pros and cons of using asynchronous frameworks for web development in the Python ecosystem. Now customize the name of a clipboard to store your clips. I have now updated the examples to work with the most recent version at the time of this writing 3.