Modifying a list in python by passing it to a function

Question

I have the following python code:

def make_great(l):
    l = [\'The great \' + magician for magician in l]

magicians = [\'Tom\']
make_great(magicians)
print(mag         


        

Answer 1

Your function is not returning anything. You can either have your print statement in the function or return the modified list and then print it

Answer 2

When you assign it to l, you are redefining l, not modifying it. Use l[:] instead:

def make_great(l):
    l[:] = ['The great ' + magician for magician in l]

You could also return the list and redefine magicians:

def make_great(l):
    return ['The great ' + magician for magician in l]

magicians = ['Tom']
magicians = make_great(magicians)
print(magicians)

In that case, you could assign magicians to make_great(['Tom']):

magicians = make_great(['Tom'])
print(magicians)

Answer 3

def make_great(l):
    return ['The great ' + magician for magician in l]

magicians = ['Tom']
magicians = make_great(magicians)
print(magicians)

The make_great function duplicates your array, so you need to return and assign the result to magicians.

You can check How do I pass a variable by reference? for passing reference or values in functions