what is a decorator for in python code example
Example 1: 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")
Example 2: decorators in python
'pass function which we want to decorate in decorator callable object'
def our_decorator(func):
def wrapper(x):
if x%2==0:
return func(x)
else:
raise Exception("number should be even")
return wrapper
@ our_decorator
def func(x):
print(x,"is even")
func(2)
func(1)
' if you do not want to use @'
func=our_decorator(func)
func(2)
Example 3: 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)
with open(logfile, 'a') as opened_file:
opened_file.write(log_string + '\n')
return func(*args, **kwargs)
return wrapped_function
return logging_decorator
@logit()
def myfunc1():
pass
myfunc1()
@logit(logfile='func2.log')
def myfunc2():
pass
myfunc2()