如果Python3类中有__call__方法,那么此类实例的行为类似于函数并且可以像函数一样被调用。当实例作为函数被调用时,如果定义了此方法,则x(arg1, arg2, …)是x.__call__(arg1, arg2, …)的简写。
为了将一个类实例当作函数调用,我们需要在类中实现__call__()方法。该方法的功能类似于在类中重载()运算符,使得类实例对象可以像调用普通函数那样,以”对象名()”的形式使用。
以下为测试代码:
var = 2 if var == 1: # https://www.geeksforgeeks.org/__call__-in-python/ class Example: def __init__(self): print("Instance Created") # Defining __call__ method def __call__(self): print("Instance is called via special method") e = Example() # Instance created # __init__ method will be called e() # Instance is called via special method # __call__ method will be called elif var == 2: class Product: def __init__(self): print("Instance Created") # Defining __call__ method def __call__(self, a, b): # 可以定义任意参数 print(a * b) ans = Product() # Instance created # __init__ method will be called ans(10, 20) # 200 # __call__ method will be called ans.__call__(10, 20) # 等价于ans(10, 20) print("test finish")
GitHub:https://github.com/fengbingchun/Python_Test