理解Python類裝飾器 call

# coding=utf-8

# 深入理解類裝飾器
# 一：類裝飾器(都不帶引數)
class
clsdeco:
def__init__
(self, func):
self.func = func
def__call__
(self, *args, **kwargs):
print(f'running ')
self.func()
print('end')
@clsdeco  # 等價於 bar = clsdeco(bar)
defbar
():    print('do something')
# call bar()
# out:
#     running bar
#     do something
#     end
# 二：類裝飾器帶引數
class
clsdeco1:
def__init__
(self, x, y):
self.x = x
self.y = y
def__call__
(self, func, *args, **kwargs):
print(f'running ')
print(f'using x + y = ')
return func
@clsdeco1(1,2) # 等價於 bar1 = clsdeco1(1,2)(bar1)
defbar1
():    print('do something')
# call bar1()
# out:
#     running bar1
#     using x + y = 3
#     do something
# 三：類裝飾器不帶引數，被包裝物件帶引數
class
clsdeco2:
def__init__
(self, func):
self.func = func
def__call__
(self, *args, **kwargs):
print(f'running ')
self.func(*args, **kwargs)
print('end')
@clsdeco2  # 等價於bar2 = clsdeco2(bar2)
defbar2
(a,b):
print('do something')
print(f'return a + b = ')
# bar2(1,2)
# out:
#     running bar2
#     do something
#     return a + b = 3
#     end
# 四：類裝飾器帶引數且被裝飾物件也帶引數
class
clsdeco3:
def__init__
(self, x, y):
self.x = x
self.y = y
def__call__
(self, func, *args, **kwargs):
print(f'using x + y = ')
def(*args, **kwargs):
func(*args, **kwargs)
print('ending')
@clsdeco3(1, 2) # 等價於 bar3 = clsdeco3(1, 2)(bar3)
defbar3
(a, b):
print('do something')
print(f'return a + b = ')
# call bar3(1,2)
# out:
#     using x + y = 3
#     do something
#     return a + b = 3
#     ending
if __name__ == '__main__':
bar3(1,2)

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