strict_types

This is strict_types lib (which consists mostly of one decorator) I created for python that implements strict typing using type-hints. It works only with python 3.5 for now, though I think it's pssible to make it work with any version of python using function annotations syntax.

Installation

It doesn't work for now, I'll maybe fix this at some point. Now you can just copy strict_types.py your program's directory. I'm sorry for the inconvinience.

You can try installing it via pip (that doesn't work for my ubuntu machine)

pip3 install git+git://github.com/ipeterov/strict_types@maste

or by downloading .tar.gz file, unpacking it and running

python3 setup.py install

in the folder that was created after unpacking. This is not the best option, but it works on all my machines.

Usage

You can import it

from strict_types import strict_types

then use it as a decorator

@strict_types
def repeat_str(mystr: str, times: int):
    return mystr * times

and it will raise a TypeError if something of the wrong type is passed to the function e.g. repeat_str('spam', 'eggs)'

Traceback (most recent call last):
  File "strict_types.py", line 29, in <module>
    repeat_str('spam', 'eggs')
  File "strict_types.py", line 13, in type_checker
    raise TypeError('Type of {} is {} and not {}'.format(argument, argument_type, hints[argument]))
TypeError: Type of times is <class 'str'> and not <class 'int'>

Using abc (abstract base classes)

Though it is possible to use it to restrict functions input to only one type, e.g.

@strict_types.strict_types
def repeat_str(mystr: str, times: int):
    return mystr * times

the recommended way to use it is with abstract base classes

from numbers import Number # a hierarchy of numeric abstract base classes.
def mutiply(a: Number, b: Number):
    return a * b

This function will accept float, int, real, or any kind of number, but will raise an exception if something different (like function, list or string) is passed to it.