Recursion in Python. A simple example. What's wrong?

Question

Python

I do a function by the factorial of a given number

a=1
def fun(x):
  if x<=0:
    pass
  else:	
    x-=1
    global a
    a*=x
    return fun(x)
print(fun(5))

Answer 1

Why do you need a pass? Why don't you collect the result of recursions, but return the last one (which will return nothing, because it will end its work on pass?