typepy 0.2.0

A Python library for variable type checker/validator/converter at a run time.

typepy

Table of Contents

• Summary

• Features

• Usage

  • Type Check Method

  • Type Validation Method

  • Type Conversion Methods

  • For more information

• Installation

• Dependencies

  • Test dependencies

• Documentation

Summary

A Python library for variable type checker/validator/converter at a run time.

Features

• checking a value type

• validate a value for a type

• convert a value from a type to the other type

The correspondence between Python types and typepy classes are as follows:

Supported Types

Python Type	typepy: Type Class
bool	Bool
datetime	DateTime
dict	Dictionary
float/decimal.Decimal (not infinity/NaN)	RealNumber
float/decimal.Decimal (infinity)	Infinity
float/decimal.Decimal (NaN)	Nan
int	Integer
list	List
None	None
str (not null)	String
str (null)	NullString
str (IP address)	IpAddress

Usage

Type Check Method

Examples:

>>> from typepy import Integer
>>> Integer(1).is_type()
True
>>> Integer(1.1).is_type()
False

Type Validation Method

Examples:

>>> from typepy import Integer
>>> Integer(1).validate()
>>> try:
...     Integer(1.1).validate()
... except TypeError as e:
...     # validate() raised TypeError when the value unmatched the type class
...     print(e)
...
invalid value type: expected=INTEGER, actual=<type 'float'>

Type Conversion Methods

convert method

Examples:

>>> from typepy import Integer, TypeConversionError
>>> Integer("1").convert()
1
>>> try:
...     Integer(1.1).convert()
... except TypeConversionError as e:
...     # convert() raised TypeConversionError when conversion failed
...     print(e)
...
failed to convert from float to INTEGER

try_convert method

Examples:

>>> from typepy import Integer
>>> Integer("1").try_convert()
1
>>> print(Integer(1.1).try_convert())  # try_convert() returned None when conversion failed
None

force_convert

Examples:

>>> from typepy import Integer, TypeConversionError
>>> Integer("1").force_convert()  # force_convert() forcibly convert the value
1
>>> Integer(1.1).force_convert()
1
>>> try:
...     Integer("abc").force_convert()
... except TypeConversionError as e:
...     # force_convert() raised TypeConversionError when the value not convertible
...     print(e)
...
failed to force_convert to int: type=<class 'str'>

For more information

Type check/validate/convert results differed according to strict_level value which can pass to typepy classes constructors as an argument. More information can be found in the API reference.

Installation

pip install typepy

Dependencies

Python 2.7+ or 3.4+

• mbstrdecoder

• python-dateutil

• pytz

• six

Test dependencies

• pytest

• pytest-runner

• tox

Documentation

http://typepy.rtfd.io/