Python callable函数使用方法详解

def my_function():
    return "Hello, callable!"
class MyClass:
    def my_method(self):
        return "Hello from method!"
# Check functions and methods
print(callable(my_function))  # Output: True
print(callable(MyClass.my_method))  # Output: True

class CallableClass:
    def __call__(self):
        return "Hello from CallableClass!"
# Create an instance of CallableClass
obj = CallableClass()
# Check if the instance is callable
print(callable(obj))  # Output: True
# Call the instance as if it were a function
print(obj())  # Output: "Hello from CallableClass!"

def add(a, b):
    return a + b
def subtract(a, b):
    return a - b
def multiply(a, b):
    return a * b
operations = {
    "add": add,
    "subtract": subtract,
    "multiply": multiply
}
def dispatch_function(operation_name, a, b):
    func = operations.get(operation_name)
    if func and callable(func):
        return func(a, b)
    else:
        return None
print(dispatch_function("add", 5, 3))
print(dispatch_function("subtract", 8, 4))
print(dispatch_function("multiply", 6, 2))

class FunctionDispatcher:
    def __init__(self):
        self.functions = {}
    def register(self, name, func):
        self.functions[name] = func
    def __call__(self, name, *args, **kwargs):
        func = self.functions.get(name)
        if func and callable(func):
            return func(*args, **kwargs)
        else:
            return None
dispatcher = FunctionDispatcher()
def add(a, b):
    return a + b
def subtract(a, b):
    return a - b
dispatcher.register("add", add)
dispatcher.register("subtract", subtract)
print(dispatcher("add", 5, 3))
print(dispatcher("subtract", 8, 4))