Calling python function with an unknown number of arguments

Question

I am writing a little script in which I call itertools.product like so:

for p in  product(list1,list2,list3):
            self.createFile(p)

Is there a way for me to call this function without knowing in advance how many lists to include?

Thanks

Answer 1

You can use the star or splat operator (it has a few names): for p in product(*lists) where lists is a tuple or list of things you want to pass.

def func(a,b):
    print (a,b)

args=(1,2)
func(*args)

You can do a similar thing when defining a function to allow it to accept a variable number of arguments:

def func2(*args): #unpacking
   print(args)  #args is a tuple

func2(1,2)  #prints (1, 2)

And of course, you can combine the splat operator with the variable number of arguments:

args = (1,2,3)
func2(*args) #prints (1, 2, 3)

Answer 2

Use the splat operator(*) to pass and collect unknown number of arguments positional arguments.

def func(*args):
   pass

lis = [1,2,3,4,5]
func(*lis)