Again and again

We say these words again and again

But they still sound the same to me

Say these words again and again

And again and again

Keane

Recursion is a function that calls itself again and again. The standard example is the faculty of the number n. It is the product of all natural numbers less than or equal to this number n.
This function, expressed recursively in Python, looks as follows:

A problem of recursions is the slow calculation speed.