python函数修饰符@的使用方法解析

def log(func):
  def wrapper():
    print('log开始 ...')
    func()
    print('log结束 ...')
  return wrapper
@log
def test():
  print('test ..')
test()

log开始 ...
test ..
log结束 ...

def log(func):
  def wrapper():
    print('log开始 ...')
    func()
    print('log结束 ...')
  return wrapper
@log
def test1():
  print('test1 ..')

def test2():
  print('test2 ..')
print(test1.__name__)
print(test2.__name__)

wrapper
test2

from functools import wraps

def log(func):
  @wraps(func)
  def wrapper():
    print('log开始 ...')
    func()
    print('log结束 ...')
  return wrapper
@log
def test1():
  print('test1 ..')

def test2():
  print('test2 ..')

print(test1.__name__)
print(test2.__name__)

test1
test2

from functools import wraps
def log(func):
  @wraps(func)
  def wrapper(*args,**kwargs):
    print('log开始 ...',func.__name__)
    ret = func(*args,**kwargs)
    print('log结束 ...')
    return ret
  return wrapper
@log
def test1(s):
  print('test1 ..', s)
  return s

@log
def test2(s1, s2):
  print('test2 ..', s1, s2)
  return s1 + s2
test1('a')
test2('a','bc')

log开始 ... test1
test1 .. a
log结束 ...
log开始 ... test2
test2 .. a bc
log结束 ...

from functools import wraps

def log(arg):  
  def _log(func):
    @wraps(func)
    def wrapper(*args,**kwargs):
      print('log开始 ...',func.__name__, arg)      
      ret = func(*args,**kwargs)
      print('log结束 ...')
      return ret
    return wrapper
  return _log
 
@log('module1')
def test1(s):
  print('test1 ..', s)
  return s

@log('module1')
def test2(s1, s2):
  print('test2 ..', s1, s2)
  return s1 + s2
test1('a')
test2('a','bc')

log开始 ... test1 module1
test1 .. a
log结束 ...
log开始 ... test2 module1
test2 .. a bc
log结束 ...