In this guide, we're going to take all of that knowledge and we're going to combine it into a single function. So we're going to create a greeting function. But this function is going to perform all of the tasks and I'm going to show you how you can work with all of those various types of function arguments at the same time.

So you say def greeting, I'm going to start off with a positional arguments you say time of day then I'm going to give a single Asterix here and to say args by following the common convention and this is going to take in the user's name and then I'm going to work with keyword arguments so we're going to use double asterisks kwargs and then from there we are going to provide the function body.

def greeting(time_of_day, *args, **kwargs):

So the behavior that I'm looking for is I want to print out a greeting to the screen for the user and then I want to iterate through the key-value pair of arguments and this is going to be a task list. And so I'm going to start off with the traditional print statement so I'll use a formatted string here so I'll say f and then Hi and then inside of this I'm going to use a string literal and pass in a join statement like we've done before.

So I'm going to join the args which is going to take in the full set of arguments and this is going to be the user's name. So this could be their first name, their first and last name, their first middle and last name, it doesn't matter it will work for any type of user. So say hi and then print out their name and then I'll say I hope you are having a great and then put inside the time of day and that will end our greeting.

def greeting(time_of_day, *args, **kwargs):
  print(f"Hi {' '.join(args)}, I hope that you're having a good {time_of_day}")

Now I'll give a couple more lines and this is where we're going to work with our keyword arguments. So I'm going to first check to see if there are keyword arguments because they are optional. So I'm going to say if there are any keyword arguments then I want to print out a task list. So I'm gonna say print and then say your tasks for the day are, and then it's simply going to print out that list.

We're going to implement a loop, and so this is going back to what we learned when we talked about looping over dictionaries because remember a keyword argument does return a dictionary to us. So I'll say for the key and the value and I'm just going to say key and val in our keyword arguments and remember that we can't simply list over a loop over the dictionary just by itself. We also have to grab the items and so I'm going to say in keyword argument items and then from here we're going to print the values out.

So I'm just going to say print and we'll use a formatted string once again and I'll say key and then from there let's just give a little arrow. So this is going to be the task and then it's going to be whatever the value is. And so then I'll say val and that should be all that we need to do.

for key, val in kwargs.items():
  print(f"{key} => {val}")

So let's come down and let's test this out by actually calling the functions. I'm going to call greeting and pass in some values, I'm going to use a slightly different syntax for passing in these values. Any time that you see a large number of arguments being passed into a function like we're going to have right here then you usually are going to want to place them on different lines simply for readability.

So let's pass in morning, this will be the time of day add comma at the end and then let's move down to the next line. And we're going to line these up and so now we can put in our name. So put in Kristine followed by Hudgens. And then let's come down. So so far if you notice the way I'm organizing these function calls is I'm passing in first the positional argument because that one does need to be placed at the very start of our function call and then I'm passing in the args. So this is our set of unpacked items that we're going to pass in right here. So this is the name. And lastly, as you may have guessed I'm going to pass in our keyword arguments.

So I can say the first task is going to be empty dishwasher and then the second task is going to be, take the pupper outside, and the third one is going to be math homework and then from there that is going to be the end of our function call. So just in review we have started with a positional argument then we passed in a set of items or which is going to be converted into a tuple of arguments and then we passed in a full set of keyword argument.

So if everything works here we should see a greeting followed by a full set of the arguments. If I run this you can see that that worked perfectly.

It says Hi Kristine Hudgens, I hope you're having a great morning Your tasks for the day are: first to empty the dishwasher, second take pupper outside, and third math homework so this works perfectly and in review you can see that we took each one of the potential argument types. We took a positional argument a unpacked set of items and then also our keyword arguments and we were able to combine all of those into a single Python function.

Code

def greeting(time_of_day, *args, **kwargs):
  print(f"Hi {' '.join(args)}, I hope that you're having a good {time_of_day}.")

  if kwargs:
    print('Your tasks for the day are:')
    for key, val in kwargs.items():
      print(f'{key} -> {val}')


greeting('Morning',
         'Kristine', 'Hudgens',
         first = 'Empty dishwasher',
         second = 'Take pupper out',
         third = 'math homework')