# a function definition typically looks like this:
def func(): # No parameters
    # do this
    ...
def func (x): # One Parameter x
    ...
def func(x, y, z): # Parameter list x, y, z
    ...
# Scope is literally like the
# scope of where you use something.
# in a function what that means is
# everything you want the function to
# do is indented into it right?
# so everything within the function
# is known within the SCOPE of the
# function
def func1():
    local_variable = 1
    # local_variable is within the func scope
    # I can't use local_variable anywhere
    # outside this function because Pycharm
    # won't know what it is.
# local_variable
# uncomment that ^ notice how python doesn't
# know what it is

# Invocation means I'm calling a function.
# I want the function to execute.
def f(x):
    return x
b = f(3) # this is a function invocation
# because we are calling f(x)
# Parameter passing is the act of when
# a function is invoked, a COPY of its
# arguments is passed, given to
# the function to start running and its
# parameters are going to be initialized
# with copies of the arguments.
# So in my example, 3 is the argument
# and is used to initialize parameter x
# in the function.

# The inability to write a swap function
# has been a common theme on previous tests

# Importing a file
# usually means you're
# importing a module
# in this class.
# what that means is
# modules have the
# function definitions
# and we want to be able to use
# the functions FROM that module