如何在循环中使用函数中的结果？

Question

I want to define two functions, one inside the other, and loop it until it reaches the value I'm looking for. However, the values in the function are not accessible from outside the function, so the codes do not work properly. Can I get some help with that? Is there a way to achieve this?

def count_div(number):
    counter = 0
    for ite in range(1,number+1):
        if number % ite == 0:
            counter += 1
        else:
            continue
    else:
        #print(number, counter)
        return counter

def sum_of(order):
    num = 0
    for a in range(order+1):
        num = num + a  
    count_div(num)

#sum_of(7)

for o1 in range(100):
    if sum_of(o1) == 20:
        print(o1)
        break
    else:
        continue
else:
    print('can\'t reach') 

there is my work but in for loop sum_of func. not give an usable result for comparison.. Thanks You.

Answer 1

You need to return the result of the function you call.

def sum_of(order):
    num = 0
    for a in range(order+1):
        num = num + a
    return count_div(num)

When there is no explicit return statement in a function python automatically returns None . Therefore the line if sum_of(o1) == 20: was comparing None to 20 every iteration.

Just FYI for the function count_div you can use sum for a more pythonic approach:

sum(not number%(n+1) for n in range(number)

And sum_of this is just adding all positive integers from 1-n. This can also be done using this equation n*(n+1)//2 for sake of efficiency vs a looping method, thus making sum_of pretty much irrelevant.

def count_div(num):
    return sum(not num%(n+1) for n in range(num*(num+1)//2))

Then for your last loop:

for o1 in range(100):
    if count_div(o1) == 20:
        print(o1)
        break

Answer 2

Your sum_of function is not returning anything which is why your if condition will never work. Add a return on the last line in sum_of function:

return count_div(num)

Also you have lots of unnecessary else: statements which you should remove, here is an example:

def count_div(number):
    counter = 0
    for ite in range(1,number+1):
        if number % ite == 0:
            counter += 1

    #print(number, counter)
    return counter

def sum_of(order):
    num = 0
    for a in range(order+1):
        num = num + a  
    return count_div(num)

#sum_of(7)

for o1 in range(100):
    if sum_of(o1) == 20:
        print(o1)
        break
else:
    print('can\'t reach')