3 Answers
+ 5
It's a tricky concept, where you should always think of defining the base case, where the recursion ends. Otherwise...:
https://www.sololearn.com/discuss/307407/?ref=app
+ 2
https://www.sololearn.com/Discuss/1172346/?ref=app
Can't remember who started this, but this is recursion. A function that calls itself from within itself
+ 1
Recursion is a programming concept not only in Python which is basically about a function calling itself. Uses for this are pretty limited, a common example is finding a factorial (which can be done with loops too).