#回調(diào)函數(shù)1
#生成一個(gè)2k形式的偶數(shù)
def double(x):
    return x * 2
    
#回調(diào)函數(shù)2
#生成一個(gè)4k形式的偶數(shù)
def quadruple(x):
    return x * 4
 
callback_demo.py`
 
from even import *
 
#中間函數(shù)
#接受一個(gè)生成偶數(shù)的函數(shù)作為參數(shù)
#返回一個(gè)奇數(shù)
def getOddNumber(k, getEvenNumber):
    return 1 + getEvenNumber(k)
    
#起始函數(shù)，這里是程序的主函數(shù)
def main():    
    k = 1
    #當(dāng)需要生成一個(gè)2k+1形式的奇數(shù)時(shí)
    i = getOddNumber(k, double)
    print(i)
    #當(dāng)需要一個(gè)4k+1形式的奇數(shù)時(shí)
    i = getOddNumber(k, quadruple)
    print(i)
    #當(dāng)需要一個(gè)8k+1形式的奇數(shù)時(shí)
    i = getOddNumber(k, lambda x: x * 8)
    print(i)
    
if __name__ == "__main__":
    main()

def apply_ascyn(func, args, callback):
    """ 
    func 函數(shù)的是處理的函數(shù)
    args 表示的參數(shù)
    callback 表示的函數(shù)處理完成后的 該執(zhí)行的動(dòng)作
    """
    result = func(*args)
    callback(result)
 
def add(x, y):
    return x + y
 
def print_result(result):
    print(result)
 
apply_ascyn(add, (2, 3), callback=print_result)

def appy_async(func, args, *, callback):
    result = func(*args)
    #異步執(zhí)行的函數(shù) 同時(shí)將執(zhí)行后返回到這個(gè)早從這個(gè)函數(shù)跳出去
    callback(result)
 
def add(x ,y):
    return x + y
 
class ResultHandler(object):
    def __init__(self):
        self.sequence = 0
 
    def handle(self, result):
        self.sequence += 1
        print("[{}] Got: {}".format(self.sequence, result))
 
resultHandler = ResultHandler()
appy_async(add, (2,3), callback=resultHandler.handle)

def apply_async(func, args, *, callback):
    result = func(*args)
    callback(result)
 
def add(x ,y):
    return x + y
 
def make_handler():
    sequence = 0
    def handler(result):
        nonlocal sequence
        sequence += 1
        print("[{}] Got:{}".format(sequence, result))
    return handler
 
handler = make_handler()
apply_async(add, (2,3), callback=handler)

def apply_async(func, args, *, callback):
    result = func(*args)
    callback(result)
 
def add(x, y):
    return x + y
 
def make_handler():
    sequence = 0
    while True:
        result = yield
        sequence += 1
        print("[{}] Got:{}".format(sequence, result))
 
handle = make_handler()
next(handle)
 
apply_async(add, (2,3), callback=handle.send)