How to invoke a function with return statement in list comprehension?

How to invoke a function with return statement in list comprehension? - Printable Version

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How to invoke a function with return statement in list comprehension? - maiya - Jul-17-2021

Hi All,

I want to invoke a function with return statement using list comprehension or even lambda (if possible) for the better performance. Below is code snippet where I am trying to achieve that in list comprehension where if that function return Fail then break the flow and control move to next statement.

def func(var):
    return True if var % 2 else False

l = [2, 2, 3, 4]
new_list = [out for var in l out = func(var) if out == False break]
print(new_list)

Output:
[True, True]

But then I could not able to achieve the desired result, I would really appreciate if any suggestion on this.

Similarly how to assign a value using list comprehension?

Regards,
Maiya

RE: How to invoke a function with return statement in list comprehension? - Yoriz - Jul-17-2021

from itertools import takewhile


def func(number):
    return True if number % 2 else False


numbers = [2, 2, 3, 4]
new_list = [number for number in numbers if not func(number)]
print(new_list)

new_list2 = list(takewhile(lambda number: not func(number), numbers))
print(new_list2)

Output:[2, 2, 4]
[2, 2]

RE: How to invoke a function with return statement in list comprehension? - maiya - Jul-17-2021

I want to store the return value from the function not the list numbers.

RE: How to invoke a function with return statement in list comprehension? - Yoriz - Jul-17-2021

from itertools import takewhile


def func(number):
    return True if number % 2 else False


numbers = [2, 2, 3, 4]
new_list = [func(number) for number in numbers if not func(number)]
print(new_list)

new_list2 = [func(number) for number in takewhile(
    lambda number: not func(number), numbers)]
print(new_list2)

Output:[False, False, False]
[False, False]

RE: How to invoke a function with return statement in list comprehension? - maiya - Jul-17-2021

(Jul-17-2021, 12:01 PM)Yoriz Wrote:

from itertools import takewhile


def func(number):
    return True if number % 2 else False


numbers = [2, 2, 3, 4]
new_list = [func(number) for number in numbers if not func(number)]
print(new_list)

new_list2 = [func(number) for number in takewhile(
    lambda number: not func(number), numbers)]
print(new_list2)

Output:[False, False, False]
[False, False]

Could you please explain the code sir? and here is that really required to call func method twice?
Regards,
Maiya