[Python tutorial] 14. Functions

Functions

def my_function():
  print("Hello from a function")

my_function() # call a function

Arguments (args)

def my_function(fname):
  print(fname + " Refsnes")

my_function("Emil")

Number of Arguments

def my_function(fname, lname): # 2 args
  print(fname + " " + lname)

my_function("Emil", "Refsnes") # 2 args

Arbitrary Arguments, *args

tuple of args

def my_function(*kids):
  print("The youngest child is " + kids[2])

my_function("Emil", "Tobias", "Linus")

Keyword Arguments, kwargs

key = value

def my_function(child3, child2, child1):
  print("The youngest child is " + child3)

my_function(child1 = "Emil", child2 = "Tobias", child3 = "Linus")

Arbitrary Keyword Arguments, **kwargs

dictionary of arguments

def my_function(**kid):
  print("His last name is " + kid["lname"])

my_function(fname = "Tobias", lname = "Refsnes")

Default Parameter Value

def my_function(country = "Norway"):
  print("I am from " + country)

my_function("Sweden")
my_function()

Passing a List as an Argument

def my_function(food):
  for x in food:
    print(x)

fruits = ["apple", "banana", "cherry"]
my_function(fruits)

Return Values: return

def my_function(x):
  return 5 * x

print(my_function(3))

pass

def myfunction():
  pass

Recursion

defined function can call itself

def tri_recursion(k):
  if(k > 0):
    result = k + tri_recursion(k - 1)
    print(result)
  else:
    result = 0
  return result

print("\n\nRecursion Example Results")
tri_recursion(6)
# result = k: 6 + ( # result = 6+15 = 21 & code end
# result = k: 5 + ( # result = 5+10 = 15
# result = k: 4 + ( # result = 4+6 = 10
# result = k: 3 + ( # result = 3+3 = 6
# result = k: 2 + ( # result = 2+1 = 3
# result = k: 1 + ( # result = 1
# result = k: 0 -> no print)

Recursion Example Results
1
3
6
10
15
21