Imagine having a long-named or nested collection/dictionary of function objects, if I want to apply decorator to some of them based on certain conditions, I'll have to:
long_long_name[some_key][some_other, key] = my_decorator(long_long_name[some_key][some_other, key])
Is there a pythonic way / syntax-sugar to do it ? like plus-equal for addition to self ?
a = a + b # can be written as
a += b
a = b(a)
a ◯= b # something like this ?
I don't think it would be a good idea, but something similar to what you want is possible.
If you can decorate all your callables, you could add such an operation, for example with the @= operator, which is usually not defined for functions:
The first step would be to declare the decorator that you have to apply to all of your callables:
class decoratable:
def __init__(self, fn):
self.fn = fn
def __matmul__(self, other):
return decoratable(other(self.fn))
def __call__(self, *args, **kwargs):
return self.fn(*args, **kwargs)
If you manage to decorate all of your callables with this decorator, then you can use @ to combine them with other decorators:
@decoratable
def add_2(x):
return x + 2
long_long_name = {"some_key": {("other", "key"): add_2}}
Let's define an example decorator that prints when you call the function:
def printer(fn):
def wrapper(*args, **kwargs):
print(f"Calling {fn.__name__}")
return fn(*args, **kwargs)
return wrapper
Then, finally, this becomes possible:
>>> long_long_name["some_key"]["other", "key"](3)
5
>>> long_long_name["some_key"]["other", "key"] @= printer
>>> long_long_name["some_key"]["other", "key"](3)
Calling add_2
5
No, there's no built-in syntax-sugar way of doing this as of python 3.8. The built-in assignment operators are
=
+=
-=
*=
/=
%=
//=
**=
&=
|=
^=
>>=
<<=
@=
as taken from the docs from the operator library: https://docs.python.org/3/library/operator.html.