In [1]:

    

def listsum(numList):
    theSum = 0
    for i in numList:
        theSum = theSum + i
    return theSum

print(listsum([1,3,5,7,9]))


    

    




25

In [2]:

    

def listsum(numList):
    if len(numList) == 1:  # base case
        return numList[0]
    else:
        return numList[0] + listsum(numList[1:]) # change its state and move toward base case with [1:]

print(listsum([1,3,5,7,9]))


    

    




25

In [3]:

    

# base case - n < base
# n / base (division by the base will move us toward base case)
# call recursion on n/base  

def toStr(n,base):
    convertString = "0123456789ABCDEF"
    if n < base:
        return convertString[n]
    else:
        return toStr(n // base, base) + convertString[n % base]


    

In [4]:

    

print(toStr(1453,16))


    

    




5AD

In [6]:

    

def reverseStr(s):
    if len(s) == 1:
        return s
    else:
        return reverseStr(s[1:]) + s[0]


    

In [7]:

    

reverseStr("hello")


    

    
Out[7]:





'olleh'

In [ ]: