Typeerror: 'str' object not callable

See more:

Python

selenium

UI-automation

I'm writing an automated UI test for a simple Web application which uses Angular 10 on the front end. The bot needs to click a button, which produces a table on the screen, and then it looks for a specific entry on the table. I keep getting the following error when I try to run the script:

TypeError: 'str' object not callable

Below is the test code I've written so far.

import pytest
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

from selenium.webdriver import Firefox
from selenium.webdriver.common.keys import Keys

class Tags:

  starSysButton = '//li[button][1]'
  solPath = f"//td[contains(text(),'Sol')]"

@pytest.fixture
def browser():
  driver = Firefox()
  driver.implicitly_wait(10)
  yield driver
  driver.quit()

def test_basic_landing_page(browser):
  URL = 'http://localhost:4200'
  
  browser.get(URL)

  starElement = browser.find_element(By.XPATH(Tags.starSysButton))
  starElement.click()

  results = browser.find_element(By.XPATH(Tags.solPath))
  if results:
    assert results

Here is a link to Stack Overflow where I have a snap of the command prompt: python - Automated Test Halt with TypeError: 'str' object not callable - Stack Overflow[^]

What I have tried:

I created the Tags class to pass the XPATH variables to find_element instead of passing them as strings directly, but that still didn't fix the problem, and adding an implicit wait before the click didn't help, either. I'd appreciate any advice.