如何使用python将所有具有相同值的元素收集到数组中？

def collect_elements_with_same_value(arr):
    result = {}
    for element in arr:
        if element not in result:
            result[element] = [element]
        else:
            result[element].append(element)
    return list(result.values())

students = [
    {"name": "Alice", "age": 18},
    {"name": "Bob", "age": 20},
    {"name": "Charlie", "age": 18},
    {"name": "David", "age": 20},
    {"name": "Eve", "age": 18}
]

result = collect_elements_with_same_value([student["age"] for student in students])
print(result)

[[18, 18, 18], [20, 20]]