How to read values one whitespace separated value at a time?

In C++ you can read one value at a time like this:

//from console
cin >> x;

//from file:
ifstream fin("file name");
fin >> x;

I would like to emulate this behaviour in Python. It seems, however, that the ordinary ways to get input in Python read either whole lines, the whole file, or a set number of bits.

I would like a function, let’s call it one_read(), that reads from a file until it encounters either a white-space or a newline character, then stops. Also, on subsequent calls to one_read() the input should begin where it left off.
Examples of how it should work:

# file input.in is:
# 5 4
# 1 2 3 4 5
n = int(one_read())
k = int(one_read())
a = []
for i in range(n):
    a.append(int(one_read()))
# n = 5 , k = 4 , a = [1,2,3,4,5]

How can I do this?

>Solution :

Try creating a class to remember where the operation left off.

The __init__ function takes the filename, you could modify this to take a list or other iterable.

read_one checks if there is anything left to read, and if there is, removes and returns the item at index 0 in the list; that being everything until the first whitespace.

class Reader:
    def __init__(self, filename):
        self.file_contents = open(filename).read().split()

    def read_one(self):
        if self.file_contents != []:
            return self.file_contents.pop(0)

Initalise the function as follows and adapt to your liking:

reader = Reader(filepath)
reader.read_one()