Functions are an essential part of programming, as they can execute a block of code at once.
Often it's an excellent way to re-use blocks of code.
Let's give it a go and see how they work in Python.
A function is made by prefixing the
def foo(): print("Bar")
However, running our code now will not do anything since we didn't call our function yet.
To run/execute the function, we must call it somewhere in our code. In general, this happens when a specific criterion is matched, but let's just run it as is.
def foo(): print("Bar") foo()
When we run our code now, it returns
Having a function that prints out something is not convenient so let's see how we can give it data and return something.
Let's say we want to make a function that multiplies a number by itself and returns the output.
Meaning, if we put in the number 5, it should run
5x5 and return
def multiply(number): return number * number print(multiply(5))
Running this code will indeed return
We can easily have the function accept multiple arguments like so:
def multiply(number, multiplier): return number * multiplier print(multiply(5, 10))
This will return
And one cool thing we can do is send the arguments based on their key value like this.
You might not know how many arguments you're expecting in some cases, and you can prepend the argument with an asterisk (*).
def feed_animals(*animals): print(animals) print(animals) feed_animals('Cow', 'Chicken', 'Goat')
Which will return:
('Cow', 'Chicken', 'Goat') Goat
There are some more additions to functions, but this covers the basics for Python functions.