15 Levels Of Writing Python Functions

1) Basic functions with 0 arguments

def hello():
    print('hello')
    print('world')

hello()

# hello
# world

The absolute most basic function you can write — a function that takes in 0 arguments, but does only one uncustomizable thing.

2) Functions that take in 1 argument

def add10(n):
    return n + 10

print(add10(4))    # 14
print(add10(5))    # 15

Here, our function takes in one and only one argument, and adds 10 to it.

def add(a, b):
    return a + b

print(add(10, 4))      # 14
print(add(100, 5))     # 105

def average(a, b, c):
    return (a+b+c)/3

print(average(1,2,3))    # 2.0
print(average(3,4,6))    # 4.333333333

We can make functions take in as many arguments as we want them to.

We can make our functions take in default parameters, also known as optional parameters.

def greet(name, greeting='hello'):
    print(greeting, name)

greet('tim', 'hola')      # hola tim
greet('tim')              # hello tim

Here, greeting is a default parameter/optional parameter.