Closure,lambda,generator,decorator created by leonchen417 - https://repl.it/FIoG/31

Closure,lambda,generator,decorator.py

#Scope and Namespaces
animal = 'friutbat'
def print_global():
  print('inside print_global:', animal)
  
def change_and_print_global(): #error will occur if called 
  print('inside print_global:', animal)
  animal ='catfish'
  print('after change', animal)
  
def change_local():
  animal = 'hotdog'
  print('inside change_local:', animal,id(animal)) #id if this "animal" is different from global variable "animal"



# this is a inner function exmple
def knights(saying):
  def inner(quote):
    return "We are the knights who say: %s'" % quote
  return inner(saying)

say = knights('RoHa') #returns a string
print(say)

# this is a Closure
def knights2(saying):
  def inner2(): #saying is NOT pass into inner2
    return "We are the knights who say: %s'" % saying
  return inner2

say2 = knights2("Duck Duck") #say2 is a function 
print(say2())

#Anonymouse Function lambda() which means the function don't have name

def edit_story(words,funct):
  for word in words:
    print(funct(word))


#usual function way
sound = ['roro','mai-law','fo-law','hiss']
def enliven(word):
  return word.capitalize() +'!'
print(edit_story(sound,enliven))

# Anonymouse way

print(edit_story(sound, lambda word:word.capitalize()+ '!')) # lambda x, y: (x+y, x-y) show how to pass multiple args

#Generator -  a self-define range function
def my_range(first=0,last=10,step=1):
  number = first
  while number < last:
    yield number
    number +=step
ranger = my_range(1,5)
print(type(ranger)) #this is a generator object

for x in ranger:
  print(x)

for x2 in ranger:
  print(x2, 'haha')  #this shows nothing because it can only be iterate once, so this can't be re-count
  
#Decorator
def document_it(funct):
  def new_function(*args,**kwargs):
    print('Running function:' , funct.__name__)
    print('Positional arguments:', args)
    print('keyword arguments:',kwargs)
    result = funct(*args,**kwargs)
    print('Result:', result)
    return result
  return new_function
  
  
def square_it(funct):
  def new_function2(*args,**kwargs):
    print('Running function:' , funct.__name__)
    result = funct(*args,**kwargs)
    print('Result squared:', result*result)
    return result*result
  return new_function2

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

rich_add_ints = document_it(add_ints)
print(rich_add_ints(3,8))

@document_it
@square_it
def mul_ints(a,b):
  return a*b