wait

The command to execute a method or function as a condition to wait for.

Pylenium provides a Should API for Driver, Element, and Elements objects. This is the recommended way to wait for things in Pylenium.

However, you can use Selenium's ExpectedConditions class or lambdas as shown on the rest of this page.

There are two types of Wait objects:

• WebDriverWait (default)

  • Directly from Seleniujm

  • Returns WebElement and List[WebElement]

• PyleniumWait

  • Returns Element and Elements

  • Has a built-in .sleep() method

wait.until(condition) is the most common use of Wait and allows you to wait until the condition returns a non-False value.

However, both Waits require the condition to use a WebDriver. In the example below, we can pass in a lambda (aka anonymous function) where x is the WebDriver.

# .is_displayed() returns a bool, so the return value is True
py.wait().until(lambda x: x.find_element(By.ID, "foo").is_displayed())

# the WebElement is returned once the element is found in the DOM
py.wait().until(lambda x: x.find_element(By.ID, "foo"))

# because use_py=True, this will now return Element instead
# also, this will wait up to 5 seconds instead of the default in pylenium.json
py.wait(5, use_py=True).until(lambda x: x.find_element(By.ID, "foo"))

Syntax

# all 3 parameters are Optional with defaults
py.wait(timeout=0, use_pylenium=False, ignored_exceptions: list = None)

Usage

The usages are almost identical between the Wait objects, but you need to identify why you need to use a Wait in the first place. Pylenium does a lot of waiting for you automatically, but not for everything.

Remember, the biggest difference is what is returned: WebElement vs Element

Good framework and test design includes waiting for the right things. This is called Synchronization

WebDriverWait

This is the default Wait object. This will return WebElement, so you won't have Pylenium's Element commands like .hover() - that is what PyleniumWait is for.

• Using the defaults

defaults

# uses WebDriverWait and returns WebElement once '#save' is found
py.wait().until(lambda x: x.find_element(By.ID, "save")).click()

• Using custom timeout

Custom timeout

# uses WebDriverWait but overrides the default wait_time used in pylenium.json
py.wait(5).until(lambda x: x.find_element(By.ID, "login-button").is_enabled())

• Using ignored_exceptions

By default, the only exception that is ignored is the NoSuchElementException. You can change this by adding a list of Exceptions that you want your condition to ignore.

ignored_exceptions

# ignore exceptions every time the condition is executed
# also, this will return True because
    # x.title == 'QA at the Point'
# is a boolean expression
exceptions = [NoSuchElementException, WebDriverException]
py.wait(ignored_exceptions=exceptions).until(lambda x: x.title == "Pylenium.io")

• Combine arguments

exceptions = [NoSuchElementException, WebDriverException]
py.wait(7, ignored_exceptions=exceptions).until(lambda x: x.execute_script("js'")

PyleniumWait

If you want to return Pylenium objects like Element and Elements, then set use_py=True. Otherwise, it works the same way as WebDriverWait.

PyleniumWait with default timeout

py.wait(use_py=True).until(lambda x: x.find_element(By.ID, "menu")).hover()

PyleniumWait with custom timeout

py.wait(5, use_py=True).until(lambda x: x.find_element(By.ID, "menu")).hover()

• PyleniumWait also includes a .sleep() command

# time.sleep() for 3 seconds
py.wait(use_py=True).sleep(3)

Expected Conditions

Expected Conditions are a list of pre-built conditions that you can use in your Waits and can be used in either WebDriverWait or PyleniumWait to replace the lambda functions in the examples above.

from selenium.webdriver.support import expected_conditions as EC

py.wait().until(EC.title_is("Pylenium.io"))

Yields

• Any - Whatever the non-False value of the condition is

Raises

• TimeoutException if the condition is not met within the timeout time

• Depending on the condition, it would raise other Exceptions. If you know which ones are expected, you can include them in the ignored_exceptions as an argument.