Python装饰器和调用函数，带括号非括号的区别

1、装饰器带括号非括号

#不带参数的装饰器
def log4(func):
    @wraps(func)
    def inner(*args, **kwargs,):
        func(*args, **kwargs)
    return inner
@log4
def test(num):
    print('testlog4:',num,test.__name__)
test(40)


#带参数的装饰器
def log5(level):
    def log(func):
        @wraps(func)
        def inner(*args, **kwargs,):
            if level == "warn":
                print("%s is running" % func.__name__)
            func(*args, **kwargs)
        return inner
    return log
@log5(level="warn")
def test(num):
    print('testlog5:', num, test.__name__)
test(50)

不带参数的装饰器：带括号、不带括号的区别

#不带参数的装饰器：带括号、不带括号
from functools import wraps
import time

def runTime(func):
    @wraps(func)
    def inner(*args, **kwargs):
        s = time.time()
        func(*args, **kwargs)
        print(f'--> {func.__name__} RUN TIME: <{(time.time() - s)}> ')
    return inner


"""
@runTime   等同于 @runTime        => test1 = runTime(test1)
@runTime() 等同于 @inner 非装饰器  => test2 = runTime()(test2)  = inner(test2)  报错
"""

@runTime
def test1():
    pass
@runTime()
def test2():
    pass

带参数的装饰器：带括号、不带括号的区别

#带参数的装饰器：带括号、不带括号
from functools import wraps
import time

def out_runTime(name='测试'):
    def runTime(func):
        @wraps(func)
        def inner(*args, **kwargs):
            s = time.time()
            func(*args, **kwargs)
            print(f'--> {func.__name__} RUN TIME: <{(time.time() - s)}> ')
        return inner
    return runTime


"""
@out_runTime   等同于 @out_runTime         => test1 = out_runTime(test1)  报错
@out_runTime() 等同于 @runTime 返回一个装饰器 => test2 = runTime(test2)
"""

@out_runTime
def test1():
    pass

@out_runTime()
def test2():
    pass

2、调用函数带括号非括号

"""
1、不带括号时，调用的是这个函数本身，是整个函数体，是一个函数对象
2、带括号（参数或者无参），调用的是函数的执行结果
"""
def a():
      return 1
print(a)
print(a())