random factors and exporting them in python

I have been assigned a task that requires me to have a user input numbers with then get ran through a formula with a random factor. the user should then have the option to save the data to a text file. I have completed the task up until this point but I am faced with the problem of the data not being the same on the text file because of the random factor, how can I over come this? thanks.

    import random
    import os.path
    def main ():
        print ("1.input numbers")
        print ("2.run formula")
print ("3.export data")
maininput = int(input("Enter:"))
if maininput == 1:
    number ()
elif maininput == 2:
    formula ()
elif maininput == 3:
    file_check ()
elif maininput >3:
    print ("invalid number")
    return main ()

def number ():
    number.n1 = int(input("first number:"))
    number.n2 = int(input("second number:"))
    main()

def formula ():
    randomfactor = random.uniform (0.8 ,0.5)
    output = number.n1 * number.n2 * randomfactor
    print (" answer:",round (output))
    main()

def file_check ():
    file_check.file_name = input("What would you like to name the file?")
    if os.path.exists (file_check.file_name):
        print ("A file with the same name already exists")
        print ("Press 1 to overwrite")
        print ("Press 2 to choose a new file name")
        option = int(input("Enter:  "))
        if option ==1:
            export()
        elif option ==2:
            return file_check()
        elif option >2:
            return file_check()
    if not os.path.exists(file_check.file_name):
        export()

def export ():
    file = open (file_check.file_name,"w")
    randomfactor = random.uniform (0.8 ,0.5)
    output = number.n1 * number.n2 * randomfactor
    exout = round (output)
    file.write ("number:" + str(exout)+ '\n')
    file.close
    main ()




main ()