attribute_wrapper 0.2.0

Class wrapper, which maps attribute calls to HTTP API.

AttributeWrapper

This wrapper maps attribute calls to HTTP API. The package provides similar functionality as Tortilla, but it is implemented in smaller and simpler code.

This simplicity gives you ability to subclass and modify functionality as you need.

Examples

Basic access

from attribute_wrapper import HTTPWrapper

r = HTTPWrapper("http://kitakitsune.org")
data = r.get()

This will download content of http://kitakitsune.org and return it as string. The .get() call determines the HTTP method, which is used to perform the request.

Attribute path composition

The dot attribute access notation is used to compose the path of required HTTP resource. For example:

r.raw.get()

is translated to GET request for http://kitakitsune.org/raw.

Special characters

The dot notation in python is restricted only to A-Z, a-z, 0-9 and _, which may be sometimes too much restricting. Thats why the GenericWrapper has the attribute .specials, which contains mappings of special sequences to URL characters.

The .specials table is at this moment implemented by following structure:

{
    "__dot__": ".",
    "__slash__": "/",
    "__dash__": "-",
}

Which means that URL containing this substrings will be translated as expected:

r.raw.doctene_knihy__dot__txt.get()

is translated to http://kitakitsune.org/raw/doctene_knihy.txt

This functionality can be changed by replacing .specials dictionary table with something else, or with blank dictionary to disable it.

Underscore method

More complicated paths should be handled using _ method:

r._("compl?icated/$path/").get()

which is translated to http://kitakitsune.org/compl?icated/$path/.

Automatic suffix

If you work with API, which expects that each file ends with suffix like .json or .html, you can modify the .suffix attribute or add suffix parameter when you are instancing the class:

r = HTTPWrapper("http://kitakitsune.org", suffix=".txt")

# this will return content of the http://kitakitsune.org, because the suffix
# is ignored in root of the path
r.get()

# this will return http://kitakitsune.org/raw/doctene_knihy.txt
r.raw.doctene_knihy.get()

Parameters

The method handling call at last attribute accepts keyword parameters, which are sent to server as form data:

r.post(something="else")

This will send {"something": "else"} dictionary as POST data to server.

JSONWrapper

As example subclass, there is also JSONWrapper, which translates all parameters to JSON and send it as HTTP body to server. This may be specially useful with some of the REST API.

Subclassing

The code is actually really simple (138 lines!) and it should be (at least I think) easy to understand. If you need some new functionality, you can just simply subclass the GenericWrapper class and rewrite the .download_handler() method to reflect your needs.

For example - the JSONWrapper is implemented in few lines of code:

import json

class JSONWrapper(GenericWrapper):
    def download_handler(self, method, url, data):
        if data:
            data = json.dumps(data)

        headers = {
            'content-type': 'application/json'
        }

        resp = requests.request(method, url, headers=headers, data=data)

        # handle http errors
        resp.raise_for_status()

        return json.loads(resp.text)

Your code

Feel free to send pull request with you own classes (don’t forget to document it). I would like to make this package useful and I will gladly incorporate your code, so you don’t need to create your own package.

Installation

The code is hosted at PYPI, and you can easily install it using the following command:

sudo pip install attribute_wrapper

Testing

This project uses py.test for testing. Just run py.test from the root of the project:

bystrousak:/h/D/c0d3z/python/libs/attribute_wrapper,0$ py.test
============================= test session starts ==============================
platform linux2 -- Python 2.7.6 -- py-1.4.23 -- pytest-2.6.0
collected 8 items

tests/test_wrapper.py ........

=========================== 8 passed in 0.12 seconds ===========================

Changelog

0.2.0

• Added full test coverage.

• Added ValueError exception when calling the root object without method.

• Fixed some typos in comments.

• Added testing section to README.rst.

• Added special underscore method GenericWrapper._(path) for complicated paths.

0.1.2

• Added handling of HTTP errors.

0.1.1

• Fixed package metadata problems.

0.1.0

• Project created.