Do python's variable length arguments (*args) expand a generator at function call time?

Question

Consider the following Python code:

def f(*args):
    for a in args:
        pass

foo = [\'foo\', \'bar\', \'baz\']

# Python generator expressions FTW
gen          


        

Answer 1

Why not look and see what gen is in f()? Add print args as the first line. If it's still a generator object, it'll tell you. I would expect the argument unpacking to turn it into a tuple.

Answer 2

Your don't really need

gen = (f for f in foo)

Calling

f(*foo)

will output

('foo', 'bar', 'baz')

Answer 3

The generator is expanded at the time of the function call, as you can easily check:

def f(*args):
    print(args)
foo = ['foo', 'bar', 'baz']
gen = (f for f in foo)
f(*gen)

will print

('foo', 'bar', 'baz')