Create a basic function

Let's start our exploration of user-defined functions by creating and then running a very simple function.
The first thing we need to do is define our function.
When we define a function, we basically tell Python that it exists.
The def keyword is needed for this.
def is placed before a function name to define a function.
Let's create a function that greets employees after they log in.
First, we'll comment on what we want to do with this code.
We want to define a function.
Now, we'll go to a new line and use the keyword def to name our function.
We'll call it greet_employee.
Let's look at this syntax a little more closely.
After our keyword def and the function name, we place parentheses.
Later, we'll explore adding information inside the parentheses, but for this simple function, we don't need to add anything.
Also, just like we did with conditional and iterative statements, we add a colon at the end of this header.
After the colon, we'll indicate what the function will do.
In our case, we want the function to output a message once the employee logs in.
So let's continue creating our function and tell Python to print this string.
This line is indented because it's part of this function.
So what happens if we run this code?
Does it print our message?
Let's try this.
It doesn't.
That's because you also have to call your function.
You may not realize it, but you already have experience calling functions.
Print is a built-in function that we've called many times.
So to call greet_employee, we'll do something similar.
Let's go with a new line.
We'll add another comment because now our purpose is to call our function.
And then, we'll call the greet_employee function.
We'll run it again.
This time it printed our welcome message.
Great work!
We've now defined and called a function.
This was a simple function.
We're going to learn something next that will add to the complexity of the functions you write.
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