Conditional construction
The robot can use sensors not only in a cyclic design, but also without it. Before each action, the robot can check what the sensors show.
For this, a conditional construction (if) is used, which allows you to execute commands depending on the condition.
if condition:
commands that are executed if the condition is true (true)
otherwise:
commands that are executed if the condition is false (false)
If you put the word not (a logical connective meaning negation) before the condition, then the result "true" happens if the condition itself is false.