Python – 附加相似的值作为键

有时，在处理数据时，我们可能会遇到需要将特定列表和值分类为相似键的问题。这可能是计算数据的问题。就像计算选票或计算硬币一样。让我们讨论可以执行此任务的某些方式。

方法#1：使用循环
这是可以执行此任务的粗暴方式。在此，我们运行一个循环将值添加到字典值列表中，如果不存在，我们动态创建键并执行附加。

# Python3 code to demonstrate working of 
# Append Similar Values as Key
# Using loop
  
# initializing list
test_list = ['Manjeet', 'Nikhil', 'Akshat', 'Akash', 
            'Manjeet', 'Akash', 'Akshat', 'Manjeet']
  
# printing original list
print("The original list is : " + str(test_list))
  
# Append Similar Values as Key
# Using loop
res = dict()
for ele in test_list:
    try:
        res[ele].append(ele)
    except KeyError:
        res[ele] = [ele]
  
# printing result 
print("The similar values dictionary is : " + str(res)) 

输出 ：

The original list is : [‘Manjeet’, ‘Nikhil’, ‘Akshat’, ‘Akash’, ‘Manjeet’, ‘Akash’, ‘Akshat’, ‘Manjeet’]
The similar values dictionary is : {‘Nikhil’: [‘Nikhil’], ‘Manjeet’: [‘Manjeet’, ‘Manjeet’, ‘Manjeet’], ‘Akash’: [‘Akash’, ‘Akash’], ‘Akshat’: [‘Akshat’, ‘Akshat’]}

方法 #2：使用defaultdict() + 循环
上述功能的组合可以用来解决这个问题。在此，我们使用 defaultdict() 预初始化字典。

# Python3 code to demonstrate working of 
# Append Similar Values as Key
# Using defaultdict() + loop
from collections import defaultdict
  
# initializing list
test_list = ['Manjeet', 'Nikhil', 'Akshat', 'Akash', 
         'Manjeet', 'Akash', 'Akshat', 'Manjeet']
  
# printing original list
print("The original list is : " + str(test_list))
  
# Append Similar Values as Key
# Using defaultdict() + loop
res = defaultdict(list)
for sub in test_list:
    res[sub].append(sub)
  
# printing result 
print("The similar values dictionary is : " + str(dict(res))) 

输出 ：

The original list is : [‘Manjeet’, ‘Nikhil’, ‘Akshat’, ‘Akash’, ‘Manjeet’, ‘Akash’, ‘Akshat’, ‘Manjeet’]
The similar values dictionary is : {‘Nikhil’: [‘Nikhil’], ‘Manjeet’: [‘Manjeet’, ‘Manjeet’, ‘Manjeet’], ‘Akash’: [‘Akash’, ‘Akash’], ‘Akshat’: [‘Akshat’, ‘Akshat’]}