Unpacking of list in function but not needed when its done with MAP()?

Question

def ups(*name):
    for n in name:
        a=n.upper()

    return a
lis=["lan","ona"]
m=list(map(ups,lis))
print(m)

Here in the map I have not done unpacking of the list, but the same in case of function call for without Map(), (eg) like ups(*lis) is must, why is that?

Learning, Thanks

Answer 1

In addition to ksourav's answer,

• In the docs you find that map(function, iterable, ...) "Return[s] an iterator that applies function to every item of iterable, yielding the results". As ksourav points out in his answer, the items you pass are strings and thus iterables themselves - so the function just returns the last letter in uppercase, like

s = 'lan'
for char in s:
    print(char.upper())
# L
# A
# N

• What * does (in this case) is turning the argument (=string) passed into a 1-element tuple - you now iterate over the tuple and not the individual elements of the string anymore. This is why here, your function returns the whole word in uppercase letters, like

t = ('lan',)
for element in t:
    print(element.upper())
# LAN

• By the way, a more readable way of writing your function could imho be

m = list(map(lambda x: x.upper(), lis))
# or even better
m = [s.upper() for s in lis]