Question

Why is it that below code prints ‘None’ as well as what I tell it to write when no match is found?

def subStringMatchExact(target,key):
    list=[]
    for fsi in range (len(target)):
        if key==target[fsi:fsi+len(key)]:
            list=list+[fsi,]
            #return list
    if list!=[]:
        return list
    else:
        print 'no match found'

print subStringMatchExact("banana","x")

Answer 1

Because there is a implicit return None at the end of every function. This means that when you don’t return anything, as in the else block of your example, your function returns None anyway. So, subStringMatchExact("banana","x") returns None and this gets printed.