Answers for "examples of decorators in python"

decorator python

def our_decorator(func):
    def function_wrapper(x):
        print("Before calling " + func.__name__)
        func(x)
        print("After calling " + func.__name__)
    return function_wrapper

@our_decorator
def foo(x):
    print("Hi, foo has been called with " + str(x))

foo("Hi")

decorators in python

'pass function which we want to decorate in decorator callable object'
def our_decorator(func):  # func is function to be decorated by decorator
  
  def wrapper(x):       # x is parameter which is passed in func
    if x%2==0:
      return func(x)
    else:
      raise Exception("number should be even")
  return wrapper

@ our_decorator
def func(x):         # actual function 
  print(x,"is even")
func(2)
func(1)

' if you do not want to use @'
func=our_decorator(func)
func(2)

python decorators

# decorators are user to decorate functions like what to do before/after calling the function
import time

def delay_decorator(function):
    def wrapper_function():
        print("-----------------------I am gonna greet you--------------------------")
        time.sleep(2)# waits for 2 seconds
        function()   # calls the function
        time.sleep(1)# waits for 1 sec
        print("------------------How do you feel about that greet?-------------------")
    return wrapper_function

@delay_decorator
def greet():
    print("Helllllloooooooooo")

greet()

decorators in python

# This function take input from user and return
# list of 0 and 1, zero represents odd number
# and 1 represents even number
def deco(func):
    def wrap(lst):
        x = [1 if i % 2 == 0 else 0 for i in lst]
        return x
        func(lst)
    return wrap

@deco   
def display(l):
    return (l)

a = [int(x) for x in input("Enter number of elements : ").split(",")]
print(display(a))

decorators in python

# this functon converts any string into uppercase
def deco(function):
    def wrap(s):
        return s.upper()
        function(s)
    return wrap

@deco
def display(s):
    return s 
print(display("not bad"))

examples of function decorators in Python

from functools import wraps

def logit(logfile='out.log'):
    def logging_decorator(func):
        @wraps(func)
        def wrapped_function(*args, **kwargs):
            log_string = func.__name__ + " was called"
            print(log_string)
            # Open the logfile and append
            with open(logfile, 'a') as opened_file:
                # Now we log to the specified logfile
                opened_file.write(log_string + 'n')
            return func(*args, **kwargs)
        return wrapped_function
    return logging_decorator

@logit()
def myfunc1():
    pass

myfunc1()
# Output: myfunc1 was called
# A file called out.log now exists, with the above string

@logit(logfile='func2.log')
def myfunc2():
    pass

myfunc2()
# Output: myfunc2 was called
# A file called func2.log now exists, with the above string