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")
python装饰器
# 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()
装饰器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")
python函数装饰器
#Decorator are just function that take function as first
#parameter and return a function
def logging(f):
def decorator_function(*args, **kwargs):
print('executing '+f.__name__)
return f(*args, **kwargs)
return decorator_function
#Use it like this
@logging
def hello_world():
print('Hello World')
#calling hello_world() prints out:
#executing hello_world
#Hello World
python中的装饰器
'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装饰器
# Decorator with arguments
import functools
# First function takes the wanted number of repetition
def repeat(num_times):
# Second function takes the function
def decorator_repeat(func):
# Third function, the wrapper executes the function the number of times wanted
# functools decorator to print the true name of the function passed instead of "wrapper"
@functools.wraps(func)
def wrapper(*args, **kwargs):
for _ in range(num_times):
result= func(*args, **kwargs)
return result
return wrapper
return decorator_repeat
# Our function using the decorator
@repeat(num_times= 3)
def greet(name):
print(f"Hello {name}")
greet("thomas")
蟒蛇的装饰
from functools import wraps
def debug(func):
@wraps(func)
def out(*args, **kwargs):
print('hello world')
return func(*args, **kwargs)
return out
@debug
def add(x, y):
return x + y