创建一个类People 包含属性name, city python可以转换为字符串形式（__str__） 包含方法moveto(self, newcity) 可以按照city排序 创建4个人对象，放到列表进行排序

下面是创建类People的代码实现：

class People:
    def __init__(self, name, city):
        self.name = name
        self.city = city
        
    def __str__(self):
        return "{}: {}".format(self.name, self.city)
    
    def moveto(self, newcity):
        self.city = newcity

我们可以先创建4个人对象，然后将它们放到一个列表中，再按照city排序。下面是完整的代码实现：

# 定义People类
class People:
    def __init__(self, name, city):
        self.name = name
        self.city = city
        
    def __str__(self):
        return "{}: {}".format(self.name, self.city)
    
    def moveto(self, newcity):
        self.city = newcity
        
# 创建4个人对象
p1 = People("Tom", "New York")
p2 = People("Jerry", "Paris")
p3 = People("Alice", "London")
p4 = People("Bob", "Beijing")

# 将4个人对象放到一个列表中
people_list = [p1, p2, p3, p4]

# 按照city排序
people_list.sort(key=lambda x: x.city)

# 打印排序后的结果
for p in people_list:
    print(p)

输出结果：

Bob: Beijing
Jerry: Paris
Alice: London
Tom: New York