What is the feature of functions in python?

There is such code:
def activator(update: Update, context: CallbackContext):

When declaring the arguments of a function is followed by a colon.
So, what is the mechanism? What is it called? What does?
April 19th 20 at 12:35
2 answers
April 19th 20 at 12:37
The annotation is called.
April 19th 20 at 12:39
Interesting article on the topic - Introduction to type annotations in Python

Find more questions by tags Python