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-2.0.0a4.tar.gz (23.9 kB view details)

Uploaded Source

Built Distribution

trafaret-2.0.0a4-py3-none-any.whl (30.0 kB view details)

Uploaded Python 3

File details

Details for the file trafaret-2.0.0a4.tar.gz.

File metadata

  • Download URL: trafaret-2.0.0a4.tar.gz
  • Upload date:
  • Size: 23.9 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: Python-urllib/3.6

File hashes

Hashes for trafaret-2.0.0a4.tar.gz
Algorithm Hash digest
SHA256 945b8c8cf7ed2964db63defa675b5c304a21af18951114e95e5ae48abe5d8b9d
MD5 c6c1ec637ea2f0b2c6a5fcbbe4fce2ff
BLAKE2b-256 516712475964b38ba4e1109691d0c916177a4256776433cbdcfb8914f909a54a

See more details on using hashes here.

File details

Details for the file trafaret-2.0.0a4-py3-none-any.whl.

File metadata

File hashes

Hashes for trafaret-2.0.0a4-py3-none-any.whl
Algorithm Hash digest
SHA256 845b84708d610e76553d38cbbbb21a6f5cf9d10688cf98aefa692e4bb0557906
MD5 443a7521d36c0b64e28dbe5a10797b66
BLAKE2b-256 d298db442acf9c826d7306bdd6ec4cf677f2cbd5b813e1a409bfaff1693c6d61

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