From 8638c00497c6dfed4f6918147985517e351fe2df Mon Sep 17 00:00:00 2001 From: DarkSun Date: Tue, 7 Jan 2020 00:58:19 +0800 Subject: [PATCH] =?UTF-8?q?=E9=80=89=E9=A2=98:=2020200106=20How=20to=20wri?= =?UTF-8?q?te=20a=20Python=20web=20API=20with=20Pyramid=20and=20Cornice?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit sources/tech/20200106 How to write a Python web API with Pyramid and Cornice.md --- ...Python web API with Pyramid and Cornice.md | 157 ++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 sources/tech/20200106 How to write a Python web API with Pyramid and Cornice.md diff --git a/sources/tech/20200106 How to write a Python web API with Pyramid and Cornice.md b/sources/tech/20200106 How to write a Python web API with Pyramid and Cornice.md new file mode 100644 index 0000000000..2b10ef953a --- /dev/null +++ b/sources/tech/20200106 How to write a Python web API with Pyramid and Cornice.md @@ -0,0 +1,157 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (How to write a Python web API with Pyramid and Cornice) +[#]: via: (https://opensource.com/article/20/1/python-web-api-pyramid-cornice) +[#]: author: (Moshe Zadka https://opensource.com/users/moshez) + +How to write a Python web API with Pyramid and Cornice +====== +Use Pyramid and Cornice to build and document scalable RESTful web +services. +![Searching for code][1] + +[Python][2] is a high-level, object-oriented programming language known for its simple syntax. It is consistently among the top-rated programming languages for building RESTful APIs. + +[Pyramid][3] is a Python web framework designed to scale up with an application: it's simple for simple applications but can grow for big, complex applications. Among other things, Pyramid powers PyPI, the Python package index. [Cornice][4] provides helpers to build and document REST-ish web services with Pyramid. + +This article will use the example of a web service to get famous quotes to show how to use these tools. + +### Set up a Pyramid application + +Start by creating a virtual environment for your application and a file to hold the code: + + +``` +$ mkdir tutorial +$ cd tutorial +$ touch main.py +$ python3 -m venv env +$ source env/bin/activate +(env) $ pip3 install cornice twisted +``` + +### Import the Cornice and Pyramid modules + +Import these modules with: + + +``` +from pyramid.config import Configurator +from cornice import Service +``` + +### Define the service + +Define the quotes service as a **Service** object: + + +``` +QUOTES = Service(name='quotes', +                 path='/', +                 description='Get quotes') +``` + +### Write the quotes logic + +So far, this only supports **GET**ing quotes. Decorate the function with **QUOTES.get**; this is how you can tie in the logic to the REST service: + + +``` +@QUOTES.get() +def get_quote(request): +    return { +        'William Shakespeare': { +            'quote': ['Love all, trust a few, do wrong to none', +            'Some are born great, some achieve greatness, and some have greatness thrust upon them.'] +    }, +    'Linus': { +        'quote': ['Talk is cheap. Show me the code.'] +        } +    } +``` + +Note that unlike in other frameworks, the **get_quote** function is _not_ changed by the decorator. If you import this module, you can still call the function regularly and inspect the result. + +This is useful when writing unit tests for Pyramid RESTful services. + +### Define the application object + +Finally, use **scan** to find all decorated functions and add them to the configuration:  + + +``` +with Configurator() as config: +    config.include("cornice") +    config.scan() +    application = config.make_wsgi_app() +``` + +The default for scan is to scan the current module. You can also give the name of a package if you want to scan all modules in a package. + +### Run the service + +I use Twisted's WSGI server to run the application, but you can use any other [WSGI][5] server, like Gunicorn or uWSGI, if you want: + + +``` +`(env)$ python -m twisted web --wsgi=main.application` +``` + +By default, Twisted's WSGI server runs on port 8080. You can test the service with [HTTPie][6]: + + +``` +(env) $ pip install httpie +... +(env) $ http GET +HTTP/1.1 200 OK +Content-Length: 220 +Content-Type: application/json +Date: Mon, 02 Dec 2019 16:49:27 GMT +Server: TwistedWeb/19.10.0 +X-Content-Type-Options: nosniff + +{ +    "Linus": { +        "quote": [ +            "Talk is cheap. Show me the code." +        ] +    }, +    "William Shakespeare": { +        "quote": [ +            "Love all,trust a few,do wrong to none", +            "Some are born great, some achieve greatness, and some greatness thrust upon them." +        ] +    } +} +``` + +### Why use Pyramid? + +Pyramid is not the most popular framework, but it is used in some high-profile projects like [PyPI][7]. I like Pyramid because it is one of the frameworks that took unit testing seriously: because the decorators do not modify the function and there are no thread-local variables, functions are callable directly from unit tests. For example, functions that need access to the database will get it from the **request** object passed in via **request.config**. This allows a unit tester to put a mock (or real) database object in the request, instead of carefully setting globals, thread-local variables, or other framework-specific things. + +If you're looking for a well-tested library to build your next API, give Pyramid a try. You won't be disappointed. + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/20/1/python-web-api-pyramid-cornice + +作者：[Moshe Zadka][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/moshez +[b]: https://github.com/lujun9972 +[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/search_find_code_python_programming.png?itok=ynSL8XRV (Searching for code) +[2]: https://opensource.com/resources/python +[3]: https://opensource.com/article/18/5/pyramid-framework +[4]: https://cornice.readthedocs.io/en/latest/ +[5]: https://en.wikipedia.org/wiki/Web_Server_Gateway_Interface +[6]: https://opensource.com/article/19/8/getting-started-httpie +[7]: https://pypi.org/