python - 如何在循环和每次迭代的条件中返回一个值？

Question

这个问题已经有答案了:

What does the "yield" keyword do in Python? (51 个回答)

已关闭 3 年前。

我有以下功能check_overload(...)我在其中检查链接是否过载或未使用下面显示的参数。

def check_overload(SR_path, Router_1, Router_2, Router_3, Router_4, step, capacity):
    iterations_array = number_iteration_tunnels(SR_path)
    load_tunnels = bandwidth_tunnel(SR_path, Router_1, Router_2, Router_3, Router_4)
    global overload_point
    overload_point = np.zeros(len(iterations_array))
    for i in range(len(iterations_array)):
        if load_tunnels[i] >= capacity - (iterations_array[i][1] * step):
            print "Link is overloaded"
            overload_point = load_tunnels[i] - step
            return overload_point
        else:
            print "Link is not overloaded"
            return 0

首先，我计算 SR_path 的每个元素的迭代次数在函数 number_iteration_tunnels(..) 中。然后，使用该函数创建的数组iterations_array ，我执行一个循环来导航该数组。

我的目标是在每次迭代中返回 overload_point如果满足条件，否则返回 0。我面临的问题是，使用此实现，该函数仅返回明显的值。我找不到一种方法来实现我的目标。

Answer 1

解决方案1

• 您可以使用 yield 实现提到的行为。
• 以下示例尝试重现您的解决方案。

def check_overload(SR_path, Router_1, Router_2, Router_3, Router_4, step, capacity):
    iterations_array = number_iteration_tunnels(SR_path)
    load_tunnels = bandwidth_tunnel(SR_path, Router_1, Router_2, Router_3, Router_4)
    global overload_point
    overload_point = np.zeros(len(iterations_array))
    for i in range(len(iterations_array)):
        if load_tunnels[i] >= capacity - (iterations_array[i][1] * step):
            print "Link is overloaded"
            overload_point = load_tunnels[i] - step
            yield overload_point
        else:
            print "Link is not overloaded"
            yield 0

for result in check_overload(*args):
    print(result) # or do whatever you want.

解决方案2

• 使用列表来存储结果。

def check_overload(SR_path, Router_1, Router_2, Router_3, Router_4, step, capacity):
    res = []
    iterations_array = number_iteration_tunnels(SR_path)
    load_tunnels = bandwidth_tunnel(SR_path, Router_1, Router_2, Router_3, Router_4)
    global overload_point
    overload_point = np.zeros(len(iterations_array))
    for i in range(len(iterations_array)):
        if load_tunnels[i] >= capacity - (iterations_array[i][1] * step):
            print "Link is overloaded"
            overload_point = load_tunnels[i] - step
            res.append(overload_point)
        else:
            print "Link is not overloaded"
            res.append(0)
    return res

for result in check_overload(*args):
    print(result) # or do whatever you want.