将数组缩减为组

from collections import defaultdict

students = [
    {"name": "Alice", "grade": 10},
    {"name": "Bob", "grade": 11},
    {"name": "Charlie", "grade": 10},
    {"name": "David", "grade": 11},
]

grouped_students = defaultdict(list)

for student in students:
    grouped_students[student["grade"]].append(student)

print(dict(grouped_students))

{
    10: [
        {"name": "Alice", "grade": 10},
        {"name": "Charlie", "grade": 10}
    ],
    11: [
        {"name": "Bob", "grade": 11},
        {"name": "David", "grade": 11}
    ]
}

students = [
    {"name": "Alice", "grade": 10},
    {"name": "Bob", "grade": None},
    {"name": "Charlie", "grade": 10},
]

grouped_students = defaultdict(list)

for student in students:
    if student["grade"] is not None:
        grouped_students[student["grade"]].append(student)

print(dict(grouped_students))

students = [
    {"name": "Alice", "grade": "10"},
    {"name": "Bob", "grade": 11},
    {"name": "Charlie", "grade": "10"},
]

grouped_students = defaultdict(list)

for student in students:
    grade = int(student["grade"])  # 统一转换为整数
    grouped_students[grade].append(student)

print(dict(grouped_students))