Typerighter

Data Types for Cynical Humans.

Welcome to Typerighter, a project that makes it easy to structure and process data using concepts from type systems.

Example

A Type.

>>> st = types.StringType(max_length=12)

A Record.

>>> class Artist(types.Record):
...     name = types.StringType(required=True)
...     website = types.URLType()
...
>>> artist_type = Artist()

Validate data.

>>> data = 'Take Five'
>>> st.validate(data)
>>>
>>> data = {
...     'name': u'American Food',
...     'website': 'http://soundcloud.com/americanfood'
... })
>>> artist_type.validate(data)

Documentation

Installation

Tagged releases are available from PyPI:

$ pip install typerighter

Python Version

TypeRighter is strictly Python 3 and up.

Optional Packages

The optional packages are for running unittests or generation documentation and are explained in the Dev Environment doc.

Quickstart

Types

This is a simple Type.

>>> st = types.StringType(max_length=12)

A Type doesn’t store data, but it knows how to validate it.

>>> st.validate('short enough')

Errors

Exceptions are specific about errors

>>> st.validate('not short enough')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/jmsdnns/Projects/typerighter/typerighter/types/base.py", line 90, in validate
    func(self, native)
File "/home/jmsdnns/Projects/typerighter/typerighter/types/domains.py", line 73, in validate_max_length
    err_msg.format(value, instance.max_length)
typerighter.exceptions.ValidationException: Value length above max: short enoughhhh > 12

Records

A Record is a structure consisting of fields, or named type instances.

>>> from typerighter import types
>>> class Artist(types.Record):
...     name = types.StringType(required=True)
...     website = types.URLType()
...
>>> artist_type = Artist()

A Record is a Type, so it doesnt store data, but knows how to validate it.

>>> data = {
...     'name': u'American Food',
...     'website': 'http://soundcloud.com/americanfood'
... })
>>> artist_type.validate(data)

Views

A View is a mutable, configurable structure that stores Record data.

>>> artist_view = artist_type.make_view(artist)
>>> artist_view.website = 'https://soundcloud.com/americanfood/my-take-on-take-on-me'

It also knows how to validate data, but assumes it validates itself.

>>> artist_view.validate()

Type

class typerighter.types.base.Type(*a, **kw)

This class represents the top, and thus most ambiguous, point of the Typerighter hierarchy.

It’s purpose is to define the baseline expectations for every other Type in this library.

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.base.UnsetValue

This class exists to put a label on the type of value that represents when a field does not _yet_ have a value.

typerighter.types.base.skip_falsy(method)

A decorator that intercepts method calls to prevent falsy inputs from being validated unnecessarily.

Primitives

class typerighter.types.primitives.BooleanType(*a, **kw)

NATIVE

alias of builtins.bool

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.primitives.FloatType(*a, **kw)

NATIVE

alias of builtins.float

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.primitives.IntegerType(*a, **kw)

NATIVE

alias of builtins.int

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.primitives.Number(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.primitives.Primitive(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.primitives.StringType(*a, **kw)

NATIVE

alias of builtins.str

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

Record

class typerighter.types.records.Record(*a, **kw)

NATIVE

alias of builtins.dict

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

Composite Types

class typerighter.types.composites.Container(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.composites.ListType(*a, **kw)

NATIVE

alias of builtins.list

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.composites.SumType(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

Time Keeping

class typerighter.types.timekeeping.DateTimeType(*a, **kw)

NATIVE

alias of datetime.datetime

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_schematic()

Returns a Type’s Schematic

class typerighter.types.timekeeping.TimeType(*a, **kw)

NATIVE

alias of datetime.time

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_schematic()

Returns a Type’s Schematic

Network Addresses

class typerighter.types.net.EmailType(*a, **kw)

NATIVE

alias of builtins.str

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

class typerighter.types.net.IPAddressType(*a, **kw)

NATIVE

alias of builtins.str

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

class typerighter.types.net.IPv4Type(*a, **kw)

NATIVE

alias of builtins.str

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

class typerighter.types.net.IPv6Type(*a, **kw)

NATIVE

alias of builtins.str

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

class typerighter.types.net.MACAddressType(*a, **kw)

NATIVE

alias of builtins.str

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

class typerighter.types.net.URLType(*a, **kw)

NATIVE

alias of builtins.str

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

Spatial

class typerighter.types.spatial.GeoPointType(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

Cryptography

class typerighter.types.cryptography.HashType(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.cryptography.MD5Type(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

class typerighter.types.cryptography.SHA1Type(*a, **kw)

NATIVE

alias of builtins.object

is_coercible(value)

Checks a value for whether or not it can be converted to the correct type. Falls back to the stricter is_type_match if self.strict is True.

Parameters

value (object) – The value to inspect

is_falsy(value)

Checks a value and responds saying whether the Type considers it falsy.

Parameters

value (object) – The value to inspect

Returns

True or False

is_type_match(value)

Checks if a value is an instance of this Type’s native type. :param object value: The value to inspect

to_native(value)

Converts a value to the native form of this type

Parameters

value (object) – The value to convert

to_primitive(value)

Converts a value to the primitive form of this type

Parameters

value (object) – The value to convert

to_schematic()

Returns a Type’s Schematic

validate(value)

This validation function is the primary function responsible for calling all associated validators and for managing any details related to aggregation of validation results.

Parameters

value (object) – The value to convert

Views

class typerighter.views.Field(name)

A descriptor used to join a mutable View instance, that stores data, with the immutable Type instance, that only defines methods for operating on data.

class typerighter.views.View(record, data=None)

A View combines a Record with a dictionary to provide an object modeled after the record that can store data in a familiar object oriented manner.

typerighter.views.make_view(record, data=None)

Takes both a record and some data and produces View instance.

Parameters

• record (Type) – The type that defines the view’s shape

• data (dict) – Any initial data for the view’s fields

Schematic

class typerighter.schematics.Schematic(klass)

A Schematic is a object that maintains a Type’s argspec. It exists as a class to provide a namespace for relevant values.

typerighter.schematics.extract_argspec(klass)

Inspects a klass and creates a dict of keyword arguments and their default values.

Parameters

klass (class) – The class definition to inspect

Returns

a dictionary of default values found in argspec for class’s init

typerighter.schematics.init_arg_capture(method)

A decorator that wraps a Type’s __init__ method for the purpose of capturing the arguments used when a Type is instantiated so it can then update the instance’s argspec with what was actually used.

Dev Environment

First, install Typerighter from source and the packages we use for development.

$ git clone https://github.com/jmsdnns/typerighter
$ cd typerighter
$ pip install -e .[dev,docs]

Verify all tests are passing

$ pytest tests
=============================== test session starts ================================
...
================================ 69 passed in 0.16s ================================

Nice.

Testing

Typerighter uses pytest.

$ pytest tests
=============================== test session starts ================================
platform darwin -- Python 3.7.4, pytest-5.2.1, py-1.8.0, pluggy-0.13.0
rootdir: ...
plugins: cov-2.8.1
collected 69 items

tests/test_booleantypes.py ....                                              [  5%]
tests/test_cache.py .                                                        [  7%]
tests/test_datetimetypes.py ..                                               [ 10%]
tests/test_emailtype.py ..                                                   [ 13%]
tests/test_ipaddresstypes.py ....                                            [ 18%]
tests/test_listtypes.py ......                                               [ 27%]
tests/test_macaddresses.py ..                                                [ 30%]
tests/test_primitives.py .........                                           [ 43%]
tests/test_records.py ............                                           [ 60%]
tests/test_schematics.py .                                                   [ 62%]
tests/test_stringtypes.py .......                                            [ 72%]
tests/test_sumtypes.py ....                                                  [ 78%]
tests/test_types.py ..........                                               [ 92%]
tests/test_urltypes.py ..                                                    [ 95%]
tests/test_views.py ...                                                      [100%]

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Nice.

Architecture

TypeRighter is a toolkit for structuring, validating, and reshaping data.

Using the toolkit means using one or more of the following things:

• Type: a classification of some data which describes how to verify arbitrary data for coherence.

• Record: a structure of data that has type instances, called _fields_, for attributes.

• Schematic: the map of arguments used to instantiate either a Type or a Record.

• View: a class that let’s you interact with a Record and some data as though it were an object instance.

Metaprogramming

The design of both Type and Record relies on metaprogramming to collect information about the way you choose to use them.

Generally speaking, metaprogramming is a way for programs to treat code like data. We can read, generate, analyze, or transform code, or modify it while running.

More specifically, TypeRighter can inspect the attributes and functions on any type at the moment a user creates one. This allows it to:

• make lists of all member variables

• make a list of all functions that start with someprefix_

And with that metadata users can:

• map out the steps for complex data validation

• generate a SQL statement automatically

• easily define datatype conversion pipelines

Attributes

All Type and Record definitions have values for:

• _validate_functions

• _schematic

Records use two extra fields:

• _fields

• _field_functions

Types

A type’s validate() function will call each function listed in _validate_functions on its input.

The metaclass can be told about new validation functions by adding functions with validate_ as a prefix, ie. validate_uppercase.

class StrictStringType(StringType):
    def validate_strict(self, value):
        ...

Records

Records introduce the concept of a field by associating a name with a type. It adds two fields of metadata to the class definition.

Let’s define a record with a string stored as field s.

class Foo(Record):
    s = StringType(required=True)

Fields defined like this are stored as _fields.

It is also possible to use a function to generate field values.

class Foo(Record):
    def field_s(self):
        return 'an actual string'

Functions that behave like fields have a prefix field_, similar to the behavior for validation functions. This field is stored as _field_functions.

Contibuting

aww yeah

License

aww yeah