Python 字典排序

一、字典按key值排序

1.实现代码：

d = {"a": 1, "c": 3, "b": 4, "d": 2}

# 基于key进行排序
def sort_dict_data(dict_data, reverse=False):
    sorted_key = sorted(dict_data.keys(), reverse=reverse)
    sorted_dict = {}
    for key in sorted_key:
        sorted_dict[key] = dict_data[key]
    return sorted_dict

result = sort_dict_data(d)
print(result)

2.输出结果：

{'a': 1, 'b': 4, 'c': 3, 'd': 2}

二、字典按value值排序

按上例，如果要按照"events"的数量进行排序，那么我们要怎么样处理呢？

1.实现代码

d = {"a": 1, "c": 3, "b": 4, "d": 2}

# 基于value进行排序
def sort_dict_by_value(dict_data, reverse=False):
    sorted_items = sorted(dict_data.items(), key=lambda x: x[1], reverse=reverse)
    sorted_dict = {}
    for item in sorted_items:
        sorted_dict[item[0]] = item[1]
    return sorted_dict

result = sort_dict_by_value(d)
print(result)

2.测试结果

{'a': 1, 'd': 2, 'c': 3, 'b': 4}

三、字段按多个value值进行排序

d = {
    "user3": {
        "name": "Tom",
        "score": 89
    },
    "user2": {
        "name": "John",
        "score": 95
    },
    "user4": {
        "name": "Adam",
        "score": 89
    },
    "user1": {
        "name": "Mary",
        "score": 90
    }
}

# 基于多个value进行排序
def sort_dict_by_multiple_value(dict_data, reverse=False):
    sorted_items = sorted(dict_data.items(), key=lambda x: (x[1]["score"], x[1]["name"]), reverse=reverse)
    sorted_dict = {}
    for item in sorted_items:
        sorted_dict[item[0]] = item[1]
    return sorted_dict

result = sort_dict_by_multiple_value(d, reverse=True)
print(result)

2. 测试结果

{'user2': {'name': 'John', 'score': 95}, 'user1': {'name': 'Mary', 'score': 90}, 'user3': {'name': 'Tom', 'score': 89}, 'user4': {'name': 'Adam', 'score': 89}}

如上，我们先按照score从高到低排序，再按照name从大到小排序。
那么问题来了，如果我们需要将name改成按从小到大排序要怎么办呢？

d = {
    "user3": {
        "name": "Tom",
        "score": 89
    },
    "user2": {
        "name": "John",
        "score": 95
    },
    "user4": {
        "name": "Adam",
        "score": 89
    },
    "user1": {
        "name": "Mary",
        "score": 90
    }
}

# 基于多个value进行排序
def sort_dict_by_multiple_value(dict_data, reverse=False):
    # if reverse:
    #     reverse = False
    # else:
    #     reverse = True
    sorted_items = sorted(dict_data.items(), key=lambda x: (-x[1]["score"], x[1]["name"].encode()), reverse=reverse)
    sorted_dict = {}
    for item in sorted_items:
        sorted_dict[item[0]] = item[1]
    return sorted_dict

result = sort_dict_by_multiple_value(d, reverse=False)
print(result)

测试结果：

{'user2': {'name': 'John', 'score': 95}, 'user1': {'name': 'Mary', 'score': 90}, 'user4': {'name': 'Adam', 'score': 89}, 'user3': {'name': 'Tom', 'score': 89}}