Selenium: element judgment

Determine if the element exists

1. I have introduced the use of the sleep() method in Python to wait: wait for a certain period of time, let the element be loaded and then execute the code
⑴ But the time when the element is loaded is not fixed, there areThe duration is sometimes short, so the time we wait is not fixed
  ⑵The best way is: Use some methods in Selenium after a certain period of timeTo determine whether the element is loaded (this is the "explicit wait" to be introduced later)
   , just keep waiting

2. In addition, when doing automation, sometimes it is necessary to judge whether the element exists, whether the iframe exists, and whether some pop-up boxes exist, so as to determine whether our operation meets expectations
⑴ ⑴It is equivalent to an assertionway up

3, selenium provides a module dedicated to element judgment: expected_conditions
⑴ ⑴The comparison used by this moduleMany scenes are used together with display waiting, and the method of display waiting is used to determine whether the element appears.
2. As for display waiting, it will be introduced later.

Introduction to common methods

1. There are many types of methods for expected_conditions.Most of them judge elements, but some judge others

method name	Description