如何在python中过滤一个条件，并根据过滤后的条件提取数据？

# 假设有一个包含学生信息的列表
students = [
    {"name": "Alice", "age": 18, "grade": "A"},
    {"name": "Bob", "age": 20, "grade": "B"},
    {"name": "Charlie", "age": 19, "grade": "A"},
    {"name": "David", "age": 21, "grade": "C"}
]

# 过滤条件：年龄大于等于20岁的学生
filtered_students = []
for student in students:
    if student["age"] >= 20:
        filtered_students.append(student)

# 打印过滤后的学生信息
for student in filtered_students:
    print(student["name"], student["age"], student["grade"])