Skip to main content

Validation and parsing library

Project description

Build status @ Circle CI Gitter Chat Latest release BSD license

Ultimate transformation library that supports validation, contexts and aiohttp.

Trafaret is rigid and powerful lib to work with foreign data, configs etc. It provides simple way to check anything, and convert it accordingly to your needs.

It have shortcut syntax and ability to express anything that you can code:

>>> from trafaret.constructor import construct
>>> validator = construct({'a': int, 'b': [str]})
>>> validator({'a': 5, 'b': ['lorem', 'ipsum']})
{'a': 5, 'b': ['lorem', 'ipsum']}

>>> validator({'a': 5, 'b': ['gorky', 9]})
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/Users/mkrivushin/w/trafaret/trafaret/__init__.py", line 204, in __call__
    return self.check(val)
  File "/Users/mkrivushin/w/trafaret/trafaret/__init__.py", line 144, in check
    return self._convert(self.check_and_return(value))
  File "/Users/mkrivushin/w/trafaret/trafaret/__init__.py", line 1105, in check_and_return
    raise DataError(error=errors, trafaret=self)
trafaret.DataError: {'b': DataError({1: DataError(value is not a string)})}

Read The Docs hosted documentation http://trafaret.readthedocs.org/en/latest/ or look to the docs/intro.rst for start.

Trafaret can even generate Trafarets instances to build transformators from json, like in json schema implementation Trafaret Schema

New

  • converters and convert=False are deleted in favor of And and &

  • String parameter regex deleted in favor of Regexp and RegexpRaw usage

  • new OnError to customize error message

  • context=something argument for __call__ and check Trafaret methods. Supported by Or, And, Forward etc.

  • new customizable method transform like change_and_return but takes context= arg

  • new trafaret_instance.async_check method that works with await

Doc

For simple example what can be done:

import datetime
import trafaret as t

date = t.Dict(year=t.Int, month=t.Int, day=t.Int) >> (lambda d: datetime.datetime(**d))
assert date.check({'year': 2012, 'month': 1, 'day': 12}) == datetime.datetime(2012, 1, 12)

Work with regex:

>>> c = t.RegexpRaw(r'^name=(\w+)$') >> (lambda m: m.group(1))
>>> c.check('name=Jeff')
'Jeff'

Rename dict keys:

>>> c = t.Dict({(t.Key('uNJ') >> 'user_name'): t.String})
>>> c.check({'uNJ': 'Adam'})
{'user_name': 'Adam'}

Arrow date checking:

import arrow

def check_datetime(str):
    try:
        return arrow.get(str).naive
    except arrow.parser.ParserError:
        return t.DataError('value is not in proper date/time format')

Yes, you can write trafarets that simple.

Project details


Release history Release notifications | RSS feed

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

trafaret-2.0.0a3.tar.gz (23.8 kB view details)

Uploaded Source

Built Distribution

trafaret-2.0.0a3-py3-none-any.whl (29.8 kB view details)

Uploaded Python 3

File details

Details for the file trafaret-2.0.0a3.tar.gz.

File metadata

  • Download URL: trafaret-2.0.0a3.tar.gz
  • Upload date:
  • Size: 23.8 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: Python-urllib/3.6

File hashes

Hashes for trafaret-2.0.0a3.tar.gz
Algorithm Hash digest
SHA256 3839118b23110597b678f45577dba6feda3344f668cf7ecf2a25b7aaf1b15a27
MD5 7e4d727f3b10f5fe482c9d455b2514d9
BLAKE2b-256 97e79bc943eee23bcc6d694cf930c6096e4b70650380bca28379908ba92e4feb

See more details on using hashes here.

File details

Details for the file trafaret-2.0.0a3-py3-none-any.whl.

File metadata

File hashes

Hashes for trafaret-2.0.0a3-py3-none-any.whl
Algorithm Hash digest
SHA256 7128bc16659c4cd88c59e40dfa8c37cecec7ea7b63a2b398b51c5ef3ad25a1cc
MD5 73092396c55d2a9a143ac012d9b691a0
BLAKE2b-256 7246c683ab25476fc37f18b8ec5315d4cc36f736fa6f01cd6dcf1d2e4867e367

See more details on using hashes here.

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page