https://github.com/neilisaac/lazycontract

Python library to define declarative contracts for serialization and deserialization
https://github.com/neilisaac/lazycontract

Last synced: 3 months ago
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Python library to define declarative contracts for serialization and deserialization

• Host: GitHub
• URL: https://github.com/neilisaac/lazycontract
• Owner: neilisaac
• License: mit
• Created: 2015-06-25T23:34:31.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2018-10-28T18:54:28.000Z (about 6 years ago)
• Last Synced: 2024-07-20T16:44:16.976Z (4 months ago)
• Language: Python
• Size: 32.2 KB
• Stars: 7
• Watchers: 3
• Forks: 3
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• awesome-python-models - lazycontract - Python library to define declarative contracts for serialization and deserialization. (Model, Schema)

README

        
lazycontract

============

### Status

[![TravisCI](https://travis-ci.org/neilisaac/lazycontract.svg)](https://travis-ci.org/neilisaac/lazycontract)

[![Code Climate](https://codeclimate.com/github/neilisaac/lazycontract/badges/gpa.svg)](https://codeclimate.com/github/neilisaac/lazycontract)

Fork the [GitHub project](https://github.com/neilisaac/lazycontract) to contribute!

### Get it

Available on [PyPI](https://pypi.python.org/pypi/lazycontract):

```

pip install lazycontract

```

### Overview

Base classes:

`StrictContract` only allows the defined attributes

`LazyContract` ignores undefined attributes

`DynamicContract` deserializes undefined attributes, but does not serialize them

### Example

```python

import json

import lazycontract

# custom property

class SloppyCSVProperty(lazycontract.LazyProperty):

    _type = list

    def deserialize(self, obj):

        return obj.split(",") if isinstance(obj, (str, unicode)) else obj

    def serialize(self, obj):

        return ",".join(str(item) for item in obj)

# custom contract

class SloppyDocument(lazycontract.LazyContract):

    title = lazycontract.StringProperty(default="new document")

    header = SloppyCSVProperty()

    body = lazycontract.ListProperty(SloppyCSVProperty())

# serialization

test1 = SloppyDocument(title="hello world", header=["first", "second"], body=[])

test1.body.append([1, 2])

test1.body.append([3, 4])

print json.dumps(test1.to_dict()) # {"body": ["1,2", "3,4"], "header": "first,second", "title": "hello world"}

# deserialization

data = json.loads('{"body": ["1,2", "3,4"], "header": "first,second", "title": "hello world"}')

test2 = SloppyDocument(data)

print test2.title  # hello world

print test2.header # [u'first', u'second']

print test2.body   # [[u'1', u'2'], [u'3', u'4']]

print type(test2)           # 

print type(test2.header)    # 

print type(test2.header[0]) # 

```

See `lazycontract/test_properties.py` for more examples of property usage.

### Goals and inspiration

 * Provide a simple means to express data contracts in code.

 * Blatantly inspired by [jsonobject](https://github.com/dimagi/jsonobject)'s API

 * Attribute serialization, de-serialization and validation should be trivial to understand and implement

 * Errors in the data or contract should be easy to debug

 * Don't impose a wire format or encoder/decoder

### TODO

 * lazy deserialization

 * timestamp properties