生成一段python写的代码，用来实现众包当中存在的任务分配

下面是一段实现任务分配的简单 Python 代码：

tasks = ['task1', 'task2', 'task3', 'task4']
assigned = {}

def assign_task(worker):
    for task in tasks:
        if task not in assigned.values():
            assigned[worker] = task
            break

workers = ['worker1', 'worker2', 'worker3']
for worker in workers:
    assign_task(worker)

print(assigned)

代码实现的功能是：给定一个任务列表 `tasks` 和一个工人列表 `workers`，每个工人只能分配一个任务，最后打印出每个工人分配的任务。