'''列表生成式[exp for val in collection if condition]生成器方法一：(exp for val in collection if condition)方法二：使用yield关键字'''a1 = (x for x in range(1, 10) if x % 2 == 0)print(a1)     #是一个对象# python2 a1.next()print(next(a1))  # python3 是直接调用next方法，到下一个print("#"*20)    # 打印20个#号for i in a1:    print(i)a2 = [x for x in range(1, 10) if x % 2 == 0]print(a2)    #是一个列表def test():    a = 1    for i in range(1, 10):        yield i   #返回之后会回到这里，执行下一行        a += 1        # return i#  return 和 yield的区别# yield可以理解成return ,但是比return多一些角色# yield每次都返回，但是下一次取值，是从yield的下一行开始执行m = test()print(m)# 九宫格def jgg():    # number = list()    count = 1    # for i in range(1, 10):    #     number.append(i)    for A in [x for x in range(1, 10)]:        for B in [x for x in range(1, 10) if x != A]:            for C in [x for x in range(1, 10) if x != A and x != B]:                for D in [x for x in range(1, 10) if x != A and x != B and x != C]:                    for E in [x for x in range(1, 10) if x != A and x != B and x != C and x != D]:                        for F in [x for x in range(1, 10) if x != A and x != B and x != C and x != D and x != E]:                            for G in [x for x in range(1, 10) if                                      x != A and x != B and x != C and x != D and x != E and x != F]:                                for H in [x for x in range(1, 10) if                                          x != A and x != B and x != C and x != D and x != E and x != F and x != G]:                                    for I in [x for x in range(1, 10) if                                              x != A and x != B and x != C and x != D and x != E and x != F and x != G and x != H]:                                        if (                                                A + B + C == D + E + F == G + H + I == A + D + G == B + E + H == C + F + I == A + E + I == C + E + G == 15):                                            print('''         -------------    第   | {1} | {2} | {3} |    {0}.   | {4} | {5} | {6} |    个   | {7} | {8} | {9} |         -------------                                                                                '''.format(count, A, B, C, D, E, F, G,                                                                                           H, I))                                            count += 1# 九宫格 end# jgg()  想要输出九宫格结果就去掉注释