Python functions

Question

I couldn't fully understand how can a function can be used as an argument in python.

Answer 1

MD Tahsin Rahman
I think you got stuck here. Right??

def add(x, y):
return x + y # This creates a new function which will return it's sum.

def do_twice(func, x, y):
return func(func(x, y), func(x, y)) # This also creates a new function which will take 3 arguments i.e the function and the values of x and y.
a = 5
b = 10

print(do_twice(add, a, b))
It will be more clear if you assume it like this.
add(add(x,y),(add(x,y)
It will first add these two values
(5+10),(5+10) which is 15 and 15.
and finally: add(15),(15)
which is 30.
In this way, functions can also be taken as arguments.
Hope you understood 🙂
You can also take help from this thread:-
https://www.sololearn.com/discuss/1670975/?ref=app

Answer 2

Functions can be used as values, which can be stored in lists and be assigned to variables.

When ever you follow the value with parentheses () , the function will be called, like calling f in:
some_list = [f]

would be done by:
some_list(...)

When you want to use a function as value you need to remember omitting the parentheses (), otherwise the function will be called and you would get the return value instead.

Answer 3

#function as argument

#function used as argument to other function
def func():
print("Inside func")

#callback function
def test(callback):
#print callback to verify the function obj
print(callback)
callback()

#call test with func as argument
test(func)