Functions

# Functions
def say_hello():
  print("hello how r u?")

say_hello()

# Indentation
def say_bye():
  print("bye bye")
  say_hello()

say_bye()

# Parameters
def say_hello(user_name):  # user_name = parameter
  print("hello", user_name, "how are you?")

say_hello("gowoon") # gowoon = argument (data)
say_hello("nico")
say_hello("lynn")
say_hello("ralph")

# Multiple Parameters
def say_hello(user_name, user_age): 
  print("hello", user_name)
  print("you are", user_age, "years old")

say_hello("gowoon", 42) 

# Default Parameters
def say_hello(user_name = "anonymous"):
  print("hello", user_name)

say_hello()

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# practice (계산기)

def plus(a = 0, b = 0):
  print(a + b)

def minus(a = 0, b = 0):
  print(a - b)

def multiply(a = 0, b = 0):
  print(a * b)

def divide(a = 0, b = 1):
  print(a / b)

def power_of(a = 0, b = 2):
  print(a ** b)

plus(1, 2)
minus(3, 4)
multiply(5, 6)
divide(7, 8)
power_of(9, 2)

plus()
minus()
multiply()
divide()
power_of()

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