The add on line 13 should work and set b as b +n in expint' scope

doubt.py

def add(b,n):
    """it gives the sum """
    b = b+n
  
def expint(b,n):
    """It gives you the value of
b multiples n times """
    if(n==0):
        b=1
    else:
        b=b * b**(n-1)
    print(b)
    add(b,n)