Python Standard Library--functools module

Functools module: Tools for managing functions

Partial object: wrapping the original function, providing a default value

Import functools# original function def myfunc (a, b=2):    """docstring for MyFunc ()."""Print ('called MyFunc with:', a, b)return# output function def show_details (name, f, is_partial=False): print (name) print (f)ifnot Is_partial:print (f.__name__)ifis_partial:print (f.func) Print (f.args) print (f.keywords)return# show_details ('MyFunc', Myfunc) # myfunc ('a',3) P1= Functools.Partial(myfunc, b=4) # The function show_details after wrapping ('partial with named', p1, True) p1 ('Passing a'# Call the wrapper after the function P1 ('Override B', b=5)

Copy the properties of the original function to the partial object

Functools.update_wrapper (p1, Myfunc)      # comment out this line, run error print (p1.__name__) print (p1.__doc__)

Wrapping a function of an instance object

classMyClass (Object): def method (self, a, B=2):        """docstring for method ()."""Print ('called method With:', a, b)returno=MyClass () p1= Functools.Partial(o.method, b=4) Show_details ('partial with named', p1, True) functools.update_wrapper (p1, o.method) print (p1.__name__) print (p1.__doc__)

@functools. Wraps Decorators

def simple_decorator (f):    @functools. wraps (f)    def decorated (a='decorated' , b=1):        print (a, b)        f (a,b =b)        return    return = simple_decorator (myfunc) print (wrapped.__name__) print (wrapped.__doc__) 

@functools. total_ordering

To add a rich comparison method to a class, the class must provide __eq__ and another rich comparison method

@functools. Cmp_to_key (cmp_obj)

Python Standard Library--functools module