Learning about python decorators

decorators.py

''' Learning about python decorators '''

def is_logged_in(func):
	def wrapper(logged_in):
		print "Checking logged in status..."
		if logged_in:
			print "Ok!"
			func(logged_in)
		else:
			print "Not logged in"

	return wrapper

@is_logged_in
def display_page(logged_in):
	print "Displaying page"


display_page(1)
print '\n'
display_page(0)

more_decorators.py

''' Let's say the API takes a list of arguments as a comma-delimited string,
	but your wrapper allows you to call a method with a list parameter or comma-delimited string parameter.
	This decorator will make sure that if it's a list, it formats it to what the API expects before calling the API.
'''

def format_params(func):
	def wrapper(params):
		if type(params) is list:
			print "Got a list, formatting to string"
			func(','.join(params))
		else:
			print "Got what I'm supposed to, send it on to the API"
			func(params)

	return wrapper

@format_params
def api_call(params):
	# printing for demo purposes
	print params


# sending a list
api_call(['a','b','c'])
print '\n'

# sending a comma-delimited string
api_call('a,b,c,d')

First file is equivalent to:

is_logged_in(display_page(1))