None problem

[gruntfutuk]

You are calling the function from a print() function, which expects a return value, doesn't receive one, so prints a default of None.

def printbeam():
    print('+----')
 
def printtwice():
    for _ in range(10):
        printbeam()
    return 'hello'
 
print(printtwice())

Return something, all call directly without print().