如何对Numpy数组中的字典按伤亡总数降序排序并提取Top5城市

我有一个terrorismData.csv文件，需要提取印度境内伤亡总数排名前5的城市，已完成大部分代码，但卡在如何对字典按值降序排序。

原代码 #

city_dict = {}
with open('terrorismData.csv', 'r', encoding='utf-8') as file_obj:
    Data = csv.DictReader(file_obj, skipinitialspace = True)
    
        
    for row in Data:
        if row['Country'] == 'India':
            if row['Killed'] == '':
                row['Killed'] = 0
            if row['Wounded'] == '':
                row['Wounded'] = 0
            
            total_casuality = int(float(row['Killed'])) + int(float(row['Wounded']))
            if row['City'] != 'Unknown':            
                if row['City'] in city_dict:
                    city_dict[row['City']] += total_casuality
                else:
                    city_dict[row['City']] = total_casuality
                
    np_city = np.array(city_dict)
    print(np_city)    

当前输出（未排序） #

{'New Delhi': 2095, 'Samastipur': 4, 'Bombay': 210, 'Imphal': 603, 'Aizawl': 2, 'Amapur': 2, 'Raisikah': 1, 'Champhai': 1, 'Jamshedpur': 32, 'Chennai': 366, 'Chiaplant': 1, 'Tindol': 7, 'Calcutta': 57, 'Tirupattur': 6, 'Gauhati': 112, 'Jorhat': 3, 'Massad': 1, 'Chandigarh': 333, 'Jodhpur': 2, 'Amritsar': 768, 'Tipaimukh': 6, 'Guwahati': 822, 'Harchowal': 1, 'Mothan Wala': 2, 'Qadian': 7, 'Baloda Bazar': 10 }

解决方案 #

你不需要将字典转成NumPy数组，直接通过Python内置的sorted()函数就能对字典按值降序排序，步骤如下：

• 对city_dict.items()进行排序，指定排序依据为键值对的值（即伤亡总数），并设置降序；
• 若只需前5个城市，对排序结果切片取前5项即可；
• Python 3.7+版本的字典本身有序，可直接将排序后的列表转为字典格式。

修正后的代码 #

import csv

city_dict = {}
with open('terrorismData.csv', 'r', encoding='utf-8') as file_obj:
    Data = csv.DictReader(file_obj, skipinitialspace=True)
    
    for row in Data:
        if row['Country'] == 'India':
            # 简化空值处理逻辑
            killed = int(float(row['Killed'])) if row['Killed'] else 0
            wounded = int(float(row['Wounded'])) if row['Wounded'] else 0
            total_casuality = killed + wounded
            
            if row['City'] != 'Unknown':
                city_dict[row['City']] = city_dict.get(row['City'], 0) + total_casuality

# 按伤亡总数降序排序
sorted_cities = sorted(city_dict.items(), key=lambda x: x[1], reverse=True)
# 提取前5名城市
top5_cities = dict(sorted_cities[:5])

print(top5_cities)
# 若需输出全部排序结果，执行 print(dict(sorted_cities))

输出示例（前5项） #

{'New Delhi': 2095, 'Guwahati': 822, 'Amritsar': 768, 'Imphal': 603, 'Chandigarh': 333}

内容的提问来源于stack exchange，提问作者Divyansh Chaudhary