如何打印出员工的层次结构树

class Employee:
    def __init__(self, name, title):
        self.name = name
        self.title = title
        self.subordinates = []

# 创建员工对象
ceo = Employee("CEO", "Chief Executive Officer")
cto = Employee("CTO", "Chief Technology Officer")
cfo = Employee("CFO", "Chief Financial Officer")
manager1 = Employee("Manager 1", "Department Manager")
manager2 = Employee("Manager 2", "Department Manager")
engineer1 = Employee("Engineer 1", "Software Engineer")
engineer2 = Employee("Engineer 2", "Software Engineer")
intern = Employee("Intern", "Intern")

# 建立层级关系
ceo.subordinates.extend([cto, cfo])
cto.subordinates.extend([manager1, manager2])
manager1.subordinates.extend([engineer1, engineer2])
manager2.subordinates.append(intern)

def print_employee_hierarchy(employee, level=0):
    print("  " * level + "- " + employee.name + " (" + employee.title + ")")
    for subordinate in employee.subordinates:
        print_employee_hierarchy(subordinate, level + 1)

print_employee_hierarchy(ceo)