从对象列表中，将几个相同(或可为空)类型的属性放入一个不同的列表中

class ExampleObject:
    def __init__(self, name, age, email):
        self.name = name
        self.age = age
        self.email = email

# 创建一个对象列表
objects = [
    ExampleObject("Alice", 30, "alice@example.com"),
    ExampleObject("Bob", 25, "bob@example.com"),
    ExampleObject("Charlie", 35, "charlie@example.com")
]

# 提取所有对象的'name'属性到一个新的列表
names = [obj.name for obj in objects]
print(names)  # 输出: ['Alice', 'Bob', 'Charlie']

# 提取所有对象的'age'属性到一个新的列表
ages = [obj.age for obj in objects]
print(ages)  # 输出: [30, 25, 35]

# 提取所有对象的'email'属性到一个新的列表
emails = [obj.email for obj in objects]
print(emails)  # 输出: ['alice@example.com', 'bob@example.com', 'charlie@example.com']

# 处理可为空的属性
class ExampleObjectWithNullable:
    def __init__(self, name, age=None, email=None):
        self.name = name
        self.age = age
        self.email = email

objects_with_nullable = [
    ExampleObjectWithNullable("Alice", 30, "alice@example.com"),
    ExampleObjectWithNullable("Bob", None, "bob@example.com"),
    ExampleObjectWithNullable("Charlie", 35, None)
]

# 提取所有对象的'name'属性到一个新的列表，忽略空值
names_with_nullable = [obj.name for obj in objects_with_nullable if obj.name]
print(names_with_nullable)  # 输出: ['Alice', 'Bob', 'Charlie']

# 提取所有对象的'email'属性到一个新的列表，忽略空值
emails_with_nullable = [obj.email for obj in objects_with_nullable if obj.email]
print(emails_with_nullable)  # 输出: ['alice@example.com', 'bob@example.com']

# 示例：处理可为空的属性
emails_with_nullable = [obj.email for obj in objects_with_nullable if obj.email is not None]