classattr 1.0.3

classattr provides tools to manage class and object attributes

ClassAttr package

This package provides tools to manage objects attributes.

It can be usefull to deal with default value attributes.

Installation

pip install classattr

Use

ClassAttr can be a parent class wich gives methods to manage attributes.

Methods are :

ClassAttr(attr={},mode=RAISE,**kwargs)

When creating an object, you can give values to attributes using a dictionary or extra parameters.

my_object = ClassAttr(x=3,y=2) or my_object = ClassAttr({'x':3,'y':2})

obj.set(attr={},mode=RAISE,**kwargs)

my_object = ClassAttr()
my_object.set(x=2)

If attribute already exist (object attribute) then modify value or create object attribute (if exist as a class attribute) else Raise a ValueError if mode is RAISE or ignore the attribute if mode is IGNORE or create the object attribute if mode is FORCE

cls.set_default(attr={},mode=RAISE,**kwargs)

set_default is a class method

ClassAttr.set_default(name='a name')

All class's object will have name attribute. If value is not set then attribute value is 'a name'

cls.clear_default()

Clear all class attributes

obj.del_attr(which,mode=RAISE)

remove an abject attribute or list of attributes

obj.get_keys()

return all class or parent class or object attributes as a list

obj.get(which)

return attributes values as a dict. wich can be a string or a list or an empty list.

If wich is an empty list, get will return all obj attributes.

Example

from classattr import ClassAttr, RAISE, FORCE

class Point(ClassAttr):

    ## class atribute, can be default value
    x = 0
    y = 0
    color = 'red'

    def __init__(self,attr = {},mode=RAISE,**kwargs):

        ClassAttr.__init__(self,attr,mode,**kwargs)


class Dot(Point):

    ## class atribute, can be default value
    radius = 1

    def __init__(self,attr = {},mode=RAISE,**kwargs):

        ClassAttr.__init__(self,attr,mode,**kwargs)


p = Point(y=3)
print('x = {}, y = {}'.format(p.x,p.y))

p.set(x=6)
p.set({'y':8})
print('x = {}, y = {}'.format(p.x,p.y))

p.set(z=4,mode=FORCE)
print(p.get_keys())
print(p.get())

d = Dot(x=12,y=24,radius=3)
print('x = {}, y = {}, r = {}'.format(d.x,d.y,d.radius))

d.set(radius=1.5)
d.color = 'blue'
print(d.get())

d.set(unknown_var = 53) # raise an error, if you want to create use mode=FORCE