Why is my code acting differently if I edit a varibale before my code gets there?

Question

Python newbie here,

I am trying to create a code that would search a name from a website and store it in a text file. If the code detects the same name in the text file it will add a certain number to käytymäärä (käytymäärä = käytymäärä + end) (käyty_määrä is a counter of how many times it has found the element and clicked it). That is because I want to skip the names that I have searched earlier.

käyty_määrä = 1

def klikkaa_nimeä():
    while True:
        try:
            #code with possible error
            ihmiset =  driver.find_element_by_xpath("/html/body/div[3]/main/div[3]/div/div/div/section/table/tbody/tr[{}]/td[1]/a".format(käyty_määrä))
        except:
            #Press button if it cant find element
            nappi = driver.find_element_by_xpath("/html/body/div[3]/main/div[3]/div/div/div/section/a")
            nappi.click() #THE CODE GETS STUCK HERE IF EDIT THE VARIABLE DOWN THERE
        else:
            #Rest of the code
            ActionChains(driver).key_down(Keys.CONTROL).click(ihmiset).key_up(Keys.CONTROL).perform() #Opens a window in a newtab
            driver.switch_to.window(driver.window_handles[1]) #Vaihtaa keskittymisen uuteen tabiin
            #Tries to find a numbers
            try:
                numbers = driver.find_element_by_xpath('/html/body/div[3]/main/div[3]/div/div/div/section/div[1]/div[1]/table/tbody/tr[1]/td[2]/a').text
            except:
                driver.close()
                break
            else:
                #Checks that it is a numbers not a name.
                first_chars = numbers[0:3]
                numeroita = str(first_chars)

                if numeroita.isdigit() is True: 

                    with open("osoitteet.txt", "r+") as osoitteet:
                        Tiedetyt_yritykset = set(name.strip() for name in osoitteet)
                    if driver.current_url in Tiedetyt_yritykset:
                        print("Yritys on katsottu läpi")
                        with open("paljonko.txt") as määrä:
                            määrä.write("\n")
                            määrä.write(str(käyty_määrä))
                            lines = määrä.readlines()
                            end = lines[-1].split(',')[0]
                            end = int(end)
                            käyty_määrä = käyty_määrä + end #THIS PART MAKES THE CODE ACT DIFFERNTLY IT MAKES IT STUCK IN A LOOP. If I remove the whole variable from here it works fine. Why does it make a difference?
                            break
                    #Wrong kind of name
                    else:
                        print("Test")

käyty_määrä = käyty_määrä + 1

This is inside of my loop and if I edit the variable käyty_määrä. I will add a number from a text file it won't work and will just get stuck in a loop. Why does it do that?

More info:

Text file:

It will add the amount of how many times it has visited the website.

I hope that my explanation is not very confusing. Please ask if this makes you confused. (:

I have two guesses what could cause it.

1. It won't recognize the variable (käyty_määrä) as a number and because of that it won't find the element.
2. A Newline in the text file is preventing the element to be not found.