Skip to main content

Thin DSL for creating input_algorithms

Project description

Input Algorithms

A DSL to assist with writing specifications describing valid data and testing that inputted data meets those defined specifications.

Why the name?

I got the inspiration from the movie Transcendence when a character says something to the effect of “We could do this if we had better input algorithms”.


Use pip!:

pip install input_algorithms

Or if you’re developing it:

pip install -e .
pip install -e ".[tests]"


Here is an example to help you use the library.

from input_algorithms.validators import Validator
from input_algorithms.dictobj import dictobj
from input_algorithms import spec_base as sb
from input_algorithms.meta import Meta
import re

meta = Meta({},[])

# 1. Create a class defining your fields.
class PersonDictObj(dictobj):
    fields = ["name", "age"]

# 2. Create custom validate methods as required.
class ValidName(Validator):
    def validate(self, meta, val):
        matcher = re.compile("^[A-Za-z\ ]+$")
        if not matcher.match(val):
            raise Exception("{0} doesn't look like a name.".format(val))
        return val

class ValidAge(Validator):
    def validate(self, meta, val):
        if val > 120:
            raise Exception("I don't believe you are that old")
        return val

# 3. Tie together the pieces.
person_spec = sb.create_spec(
    name = sb.required(sb.valid_string_spec(ValidName())),
    age = sb.and_spec(sb.integer_spec(), ValidAge()),

# 4. Have some data
data = {"name": "Ralph", "age": 23}

# 5. Normalise the data into your object
normalised = person_spec.normalise(meta, data)

# 6. Use the object!
print("Name is {0}".format(
print("Age is {0}".format(normalised.age))


To run the tests in this project, just use the helpful script:


Or run tox:


Project details

Download files

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

Source Distribution

input_algorithms-0.6.0.tar.gz (20.5 kB view hashes)

Uploaded source

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page