Recursion in Python

So, I’ve started the 100 days of code again. This is an attempt to keep the brain ticking over and keep coding fun. There are certain things I do at work, that really aren’t always that taxing. But they are necessary.

This is to explore other areas that I typically wouldn’t use. I think I haven’t used recursion before at work. This is probably unusual for developers, but it’s not really in what I do.

Python has a recursion limit of 1000 (by default), built-in. This can be overridden. However, this code shows how it works. I’ve added in the try: except: part, because I still like the program to run, even though I know it will cause a problem:

def recursion():
  print("Hello world")
  try:
    recursion()
  except RecursionError:
    print("Recursion limit reached")
    pass
  # Python has a default recursion limit of 1000
  # Base case is where you want to stop calling the recursive function

recursion()

def recursion_with_limit(count):
  print("Hello world")
  count += 1
  if count < 500:
    recursion_with_limit(count)
  else:
    print("Recursion limit reached")
    pass

count = 0 
recursion_with_limit(count)

The important thing to remember in this code is the base case, whereby you catch the condition under which you do not run the recursion again.