passing an argument to avoid a global

[Skaperen]

i have a sort key function that needs an int passed to it by the caller of sorted() that will effect how it sets up the key to be compared. i want to do this without using a global. anyone have an idea how?

[stranac]

Just create a new function:

sorted(iterable, key=lambda: key_function(x))

[Skaperen]

it's a more complex multi-line function that will ultimately be an imported module.

[stranac]

And how exactly does that stop you from wrapping it in a lambda and passing arguments to it?

[Skaperen]

i don't know how to do multi-line nested conditions and loops in a lambda.

[stranac]

In your original question you said you just need to pass an int to your function.
Where do "multi-line nested conditions and loops" come from? Has the problem changed since?

[Skaperen]

the problem has not changed. it never was limited to one line. but i didn't know someone might assume it was.

[stranac]

Maybe you could show an example of what you want to do?
At this point, I have trouble figuring out what the actual problem is.

[DeaD_EyE]

Something like this?
https://docs.python.org/3/library/operat...itemgetter

from functools import wraps


def int_itemgetter(index_or_key):
    """
    Is similar to operator.itemgetter, but it converts the element to an integer.
    """
    @wraps(int_itemgetter)
    def inner(element):
        return int(element[index_or_key])
    return inner

some_data = [(1,30,3), (4,20,6), (7,10,9)]
get_second = int_itemgetter(1)
print(sorted(some_data, key=get_second))

or written as class

class Itemgetter:
    def __init__(self, index_or_key):
        self._idx = index_or_key

    def __call__(self, element):
        return int(element[self._idx])

some_data = [(-1,30,3), (-4,20,6), (-7,10,9)]
get_first = Itemgetter(0)
print(sorted(some_data, key=get_first))

[Skaperen]

i still don't understand decorators so i'm looking at DeaD_EyE's 2nd example. suppose the sort key function is a function where i am padding those strings from re.split() that are decimal strings. there needs to be a consistent length of the padding across all records. the code that calls sorted(...,key=) would set up that length in a way that they key function could get it. then it would pad those decimal strings so they all are consistent. is that what the argument is for in line 9? i don't follow what lines 5 and 6 are doing.