how can I make a average store in a File? every time i run the code it say “No such file or directory: 'numbers.txt'”

def main():
    numbersFile = open("numbers.txt", "r")

    total = 0
    numbersLines = 0
    line = numbersFile.readLine()

    while line != "":
        numbersLines += 1
        total += int(line)
        line - numbersFile.readline()

    average = total / numbersLines
    print("the average is", average)

main()