andrew.hol...@otternetworks.de wrote:
> Hi,
>
> I'm trying to work out how to pass parameters through decorators:
>
> class Meow():
>
> def __init__(self, arg1, arg2):
> print("INIT ClassBasedDecoratorWithParams")
> print(arg1)
> print(arg2)
>
> def makebold(self, fn):
> def wrapped():
> return "<b>" + fn() + "</b>"
> return wrapped
>
> banana = Meow("foo", "bar")
> @banana.makebold("foobar")
>
> def hello():
> return "hello world"
>
> print(hello())
>
>
> Returns error:
> INIT ClassBasedDecoratorWithParams
> Traceback (most recent call last):
> foo
> File "/Users/andrew/PycharmProjects/untitled3/meow5.py", line 15, in
> <module>
> bar
> @banana.makebold("foobar")
> TypeError: wrapped() takes 0 positional arguments but 1 was given
>
>
> so I add a var to wrapped:
>
> def makebold(self, fn):
> def wrapped(flibble):
> print(flibble)
> return "<b>" + fn() + "</b>"
> return wrapped
>
> Returns error:
> INIT ClassBasedDecoratorWithParams
> Traceback (most recent call last):
> foo
> bar
> File "/Users/andrew/PycharmProjects/untitled3/meow5.py", line 16, in
> <module>
> <function hello at 0x1029198c8>
> @banana.makebold("foobar")
> File "/Users/andrew/PycharmProjects/untitled3/meow5.py", line 11, in
> wrapped
> return "<b>" + fn() + "</b>"
> TypeError: 'str' object is not callable
>
> This is confusing me. How do I get hold of the "foobar" string so I can
> use it in the decorator?
You need one more level of indirection:
class Meow():
def __init__(self, arg1, arg2):
print("INIT ClassBasedDecoratorWithParams")
print(arg1)
print(arg2)
def makebold(self, flibble):
def decorator(fn):
def wrapped():
print("flibble =", flibble)
return "<b>" + fn() + "</b>"
return wrapped
return decorator
banana = Meow("foo", "bar")
@banana.makebold("foobar")
def hello():
return "hello world"
print(hello())
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