我得到“无”而不是结果

Question

Hi im a beginner python user. I coded a thing just for practice but im getting ''none'' instead of the result. code is like this: code

i think im using str function wrong but i dont know how to fix it. thanks for your help

Answer 1

See, when you don't use the return keyword, a function returns None . So when you print a function which returns None , Then None will be printing.

So, use the return keyword.

def work_time(mathematic, chemistry, biology): 
    print(mathematic*2 + chemistry*1 + biology*(0.5))
    return mathematic*2 + chemistry*1 + biology*(0.5)
print("I will study " + str(work_time(1, 2,3) ) + " hours today")

Answer 2

I can't see an image or code but things that can result to none can be:- 1.Not returning a blue from function 2.Keeping a boolean inactive 3.Not defining codes

Answer 3

you should use return instead of print

def work_time(mathematic, chemistry, biology): 
    return mathematic*2 + chemistry*1 + biology*(0.5)
print("I will study " + str(work_time(1, 2,3) ) + " hours today")

Answer 4

none is telling you that the function is not returning a value so you must use the return keyword