[FIXED] Why won't CSS_SELECTOR locate the HTML tag all the time?

Issue

I have made a program that clicks on various Instagram prompts, and I've used CSS_SELECTOR to recognize these buttons and to click on them. The problem is, it only works sometimes. In these cases

wait.until(ec.element_to_be_clickable((By.CSS_SELECTOR, ".aOOlW.bIiDR"))).click()
wait.until(ec.element_to_be_clickable((By.CSS_SELECTOR, ".aOOlW.HoLwm"))).click()

CSS_SELECTOR works fine, but in this case

wait.until(ec.element_to_be_clickable((By.CSS_SELECTOR, "sqdOP.L3NKy.y3zKF"))).click()

It doesn't work and returns this error:

Traceback (most recent call last):
  File "C:/Users/~/PycharmProjects/InstagramBot1/main.py", line 40, in <module>
    wait.until(ec.element_to_be_clickable((By.CSS_SELECTOR, "sqdOP.L3NKy.y3zKF"))).click()
  File "C:\Users\~\PycharmProjects\InstagramBot1\venv\lib\site-packages\selenium\webdriver\support\wait.py", line 89, in until
    raise TimeoutException(message, screen, stacktrace)
selenium.common.exceptions.TimeoutException: Message: 
Stacktrace:
Backtrace:
    Ordinal0 [0x00B63AB3+2505395]
    Ordinal0 [0x00AFAE41+2076225]
    Ordinal0 [0x00A02498+1057944]
    Ordinal0 [0x00A2CB74+1231732]
    Ordinal0 [0x00A56D92+1404306]
    Ordinal0 [0x00A45A2A+1333802]
    Ordinal0 [0x00A55168+1397096]
    Ordinal0 [0x00A458BB+1333435]
    Ordinal0 [0x00A223E4+1188836]
    Ordinal0 [0x00A2323F+1192511]
    GetHandleVerifier [0x00CECB36+1554566]
    GetHandleVerifier [0x00D94A0C+2242396]
    GetHandleVerifier [0x00BF0E0B+523099]
    GetHandleVerifier [0x00BEFEB0+519168]
    Ordinal0 [0x00B002FD+2097917]
    Ordinal0 [0x00B04388+2114440]
    Ordinal0 [0x00B044C2+2114754]
    Ordinal0 [0x00B0E041+2154561]
    BaseThreadInitThunk [0x76BA6359+25]
    RtlGetAppContainerNamedObjectPath [0x775987A4+228]
    RtlGetAppContainerNamedObjectPath [0x77598774+180]


Process finished with exit code 1

What am I doing wrong, and how can I make selenium recognize every button, not just some?

(Here is my full code:)

# Importing

import requests
from bs4 import BeautifulSoup
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support import expected_conditions as ec
from selenium.webdriver.support import ui
from selenium.webdriver.support.ui import WebDriverWait

# Setting everything up

service = Service("\Program Files (x86)\chromedriver.exe")

# Asking Questions

RandTimeInvalid = True
while RandTimeInvalid:
    try:
        RandomnessTime = int(input("Select Randomness Time:"))
        RandTimeInvalid = False
    except ValueError:
        print("'Randomness Time' must be a number!")
        RandTimeInvalid = True
InstagramUsername = input("Enter Username:")
InstagramPassword = input("Enter Password:")

# Logging In

driver = webdriver.Chrome(service=service)
driver.get('https://www.instagram.com/')
wait = ui.WebDriverWait(driver, 10)
driver.maximize_window()
wait.until(ec.element_to_be_clickable((By.CSS_SELECTOR, ".aOOlW.bIiDR"))).click()
RandomnessTime = WebDriverWait(driver, (1 - RandomnessTime))
LoginUsername = ui.WebDriverWait(driver, 10).until(ec.element_to_be_clickable((By.NAME, "username"))).send_keys(InstagramUsername)
LoginPassword = ui.WebDriverWait(driver, 10).until(ec.element_to_be_clickable((By.NAME, "password"))).send_keys(InstagramPassword, Keys.ENTER)
wait.until(ec.element_to_be_clickable((By.CSS_SELECTOR, "sqdOP.L3NKy.y3zKF"))).click()
wait.until(ec.element_to_be_clickable((By.CSS_SELECTOR, ".aOOlW.HoLwm"))).click()
page = requests.get('https://www.instagram.com')
soup = BeautifulSoup(page.content, 'html.parser')
links = soup.select("span")
print(links)P[

Solution

There is nothing wrong in your code but within the locator strategies.

By.CSS_SELECTOR, ".aOOlW.bIiDR" indicates you are using classnames to locate element and these classnames are dynamically generated. So each time you access the AUT (Application Under Test), you won't find the classnames of previous executions as they are generated randomly afresh on each access.

Hence the desired elements aren't found and due to the wait wrapper you see the TimeoutException error.

Answered By - DebanjanB