PlasmaCalcs.tools.oop_tools.binding

File Purpose: binding functions to already-existing classes

Motivation: it is convenient to be able to add many functions to classes after their creation. | This facilitates a useful design principle: | - when creating a class, only define a minimal set of behaviors. | - when adding new behaviors to an existing class, bind new attributes/methods to the class, | OUTSIDE of the class definition, rather than editing the class defintion directly.

Usually it is sufficient to use this module in the following way:

from binding_module import Binding

binding = Binding(locals())

class MyClass(…):

# this class could be defined here, or literally anywhere else.

# e.g. “from module_with_class import MyClass” is fine too.

with binding.to(MyClass):

@binding

def foo1(self, *args, **kw): # any signature is fine, e.g. foo1(self, x) is fine too.

# < code for foo1 goes here

@binding

def foo2(self, *args, **kw):

# < code for foo2 goes here

# … can define any number of functions using @binding

print(MyClass.foo1)

–> (info about the bound method foo1 of MyClass, defined above)

print(foo1)

–> (NameError; foo1 is undefined in this namespace after exiting the ‘with’ block.)

It is also possible to keep a local copy(s) to the defined function(s),

or to bind them as staticmethod or classmethod. See help(Binding) for details.

Functions

bind_to(*targets)

Classes

Binding(namespace, *default_targets[, ...])