Makes such a mistake: ValueError: not enough values to unpack (expected 2, got 0)

[kalyn]

I've just started studying the software, and that's the problem, and I'm starting to deal with acmp, like everything's going to be okay, but when I want to see how it works, it's not on the website, it's not like IDLE itself, it's not going to be anything but problem. ValueError: not enough values to unpack (expected 2, got 0) Code itself:

fin  = open("input.txt")
fout = open("output.txt","w")
a,b = map(int, fin.readline().split())

fout.write(str(a+b))
fin.close()

fout.close()

Why doesn't it work? Input.txt find 4 and 5. Help the school.

[Rossere]

a,b = map(int, fin.readline().split())

Depends on what is contained in the row which is extracted by a cut fin.readline()

For example, if there's only one number or no numbers in the line, then there's a mistake, because nothing can be recorded in the variable. b or both variables a, b respectively

a, b = map(int, "".split()) # ошибка ValueError: not enough values to unpack (expected 2, got 0)
a, b = map(int, "10".split()) # ошибка ValueError: not enough values to unpack (expected 2, got 1)

a, b = map(int, "10 20".split()) # OK, все корректно

a, b = map(int, "10 20 30".split()) # ошибка ValueError: too many values to unpack (expected 2)

I'd rather read the information on the list and then work with it, depending on the size of the list.

data = list(int, fin.readline().split())