In Python, a function can call itself recursively, which means that it can execute itself multiple times until a certain condition is met. Recursion is a useful technique for solving problems that can be divided into smaller subproblems, such as sorting algorithms, tree traversal, and searching.
Here is an example of a recursive function in Python that calculates the factorial of a number:
def factorial(n):
if n == 0:
return 1
else:
return n * factorial(n — 1)
print(factorial(5)) # Output: 120
In this example, the function calls itself repeatedly with a decreasing value of n until it reaches the base case, which is n == 0. When the base case is reached, the function returns a value without making any more recursive calls.
It’s important to include a base case in a recursive function to prevent it from entering an infinite loop. The base case defines the point at which the recursion stops and the function returns a result.
Recursion can be a useful technique for solving problems, but it’s important to use it wisely. Recursive functions can be less efficient than their iterative counterparts because they require additional function calls and memory allocation. It’s also important to choose a problem that is well-suited for recursion, as not all problems can be solved effectively using this technique.
