嵌套随机化中的互斥变量定义 - Python

Question

我正在尝试返回一个 output ，其中包含使用 Python 的 random 模块从列表中选择的几个嵌套随机字符串选择，其中选择 1 的变量输出是选择 2 所独有的。本质上，我希望x_choice1在最终的 output 中永远不等于x_choice2和相同适用于y_choice1和y_choice2 。 这是一些上下文......（这都在主要的 function 中，顺便说一句）。

        x = ["x1", "x2", "x3", "x4"]

        y = ["y1", "y2", "y3", "y4"]

        # Makes random assignment to multiple x choice and y choice variables from x and y lists

        x_choice1 = random.choice(x)
        y_choice1 = random.choice(y)

        x_choice2 = random.choice(x)
        y_choice2 = random.choice(y)

        # z1 and z2 vars combine choices from both lists

        z1 = x_choice1 + " " + y_choice1

        z2 = x_choice2 + " " + y_choice2

        # While loops to make each x and y choice vars mutually 
        # exclusive with additional prints to signal when the program 
        # is re-rolling the value of vars

        while x_choice1 == x_choice2:
            print("reassigning x variables")
            x_choice1 = random.choice(x)
            x_choice2 = random.choice(x)

        while y_choice1 == y_choice2:
            print("reassigning y variables")
            y_choice1 = random.choice(y)
            y_choice2 = random.choice(y)

        # Final variables to combine nested random vars

        final1 = ["first: " + z1, "first: " + z1, "first: " + z1]

        final2 = ["second: " + z2, "second: " + z2, "second: " + z2]

        # Final random selection of nested random vars

        final_choice1 = str(random.choice(final1))

        final_choice2 = str(random.choice(final2))

        # Output both final choices

        output = final_choice1 + " " + final_choice2

        print(output)

当我删除变量的“嵌套”（分配z1和z2 ，随机选择final1和final2等）时，这完全符合我的要求。 例如...

    x = ["x1", "x2", "x3", "x4"]

    y = ["y1", "y2", "y3", "y4"]

    x_choice1 = random.choice(x)
    y_choice1 = random.choice(y)

    x_choice2 = random.choice(x)
    y_choice2 = random.choice(y)

    while x_choice1 == x_choice2:
        print("reassigning x variables")
        x_choice1 = random.choice(x)
        x_choice2 = random.choice(x)

    while y_choice1 == y_choice2:
        print("reassigning y variables")
        y_choice1 = random.choice(y)
        y_choice2 = random.choice(y)

    output1 = x_choice1 + " " + y_choice1
    output2 = x_choice2 + " " + y_choice2

    print(output1)
    print(output2)

这会输出如下内容：

reassigning x variables
reassigning x variables
x3 y1
x2 y4

每次都没有第一个 x 等于第二个 x 和 y 相同，并且如果它必须重新滚动选择也会触发消息，所以我知道它有效。

如何使第一个示例中的 while 循环以相同的方式工作？ 目前它确实触发了“重新分配变量”消息，但值总是返回相同的（例如 x4 x4，y2 y2）。

Answer 1

那是因为您的重新分配循环在您分配 z1 和 z2 之后运行，因此结果永远不会在 z1 和 z2 中结束。 最初分配 z1 和 z2 时，变量包含对 x1/x2 和 y1/y2 的当前值的引用，当 x1/x2/y1/y2 更改时，它们的值会更改，但 z1 和 z2 中的值不会更改。 这里的修复只是将 while 循环移动到 z1/z2 重新分配之前：

    x = ["x1", "x2", "x3", "x4"]

    y = ["y1", "y2", "y3", "y4"]

    # Makes random assignment to multiple x choice and y choice variables from x and y lists

    x_choice1 = random.choice(x)
    y_choice1 = random.choice(y)

    x_choice2 = random.choice(x)
    y_choice2 = random.choice(y)

    # While loops to make each x and y choice vars mutually 
    # exclusive with additional prints to signal when the program 
    # is re-rolling the value of vars

    while x_choice1 == x_choice2:
        print("reassigning x variables")
        x_choice1 = random.choice(x)
        x_choice2 = random.choice(x)

    while y_choice1 == y_choice2:
        print("reassigning y variables")
        y_choice1 = random.choice(y)
        y_choice2 = random.choice(y)

    # z1 and z2 vars combine choices from both lists

    z1 = x_choice1 + " " + y_choice1

    z2 = x_choice2 + " " + y_choice2

    # Final variables to combine nested random vars

    final1 = ["first: " + z1, "first: " + z1, "first: " + z1]

    final2 = ["second: " + z2, "second: " + z2, "second: " + z2]

    # Final random selection of nested random vars

    final_choice1 = str(random.choice(final1))

    final_choice2 = str(random.choice(final2))

    # Output both final choices

    output = final_choice1 + " " + final_choice2

    print(output)