Python|选择条件给定键大于 k 的字典

在Python中，有时我们只需要获取解决问题所需的部分字典。这个问题在 Web 开发中很常见，我们只需要获得满足某些给定标准的选择性字典。让我们讨论一些可以解决这个问题的方法。

方法 #1：使用列表推导

# Python3 code to demonstrate
# filtering of a list of dictionary
# on basis of condition
  
# initialising list of dictionary
ini_list = [{'a':1, 'b':3, 'c':7}, {'a':3, 'b':8, 'c':17},
            {'a':78, 'b':12, 'c':13}, {'a':2, 'b':2, 'c':2}]
  
# printing initial list of dictionary
print ("initial_list", str(ini_list))
  
# code to filter list
# where c is greater than 10
res = [d for d in ini_list if d['c'] > 10]
  
# printing result
print ("resultant_list", str(res))

输出：

initial_list [{‘c’: 7, ‘b’: 3, ‘a’: 1}, {‘c’: 17, ‘b’: 8, ‘a’: 3}, {‘c’: 13, ‘b’: 12, ‘a’: 78}, {‘c’: 2, ‘b’: 2, ‘a’: 2}]
resultant_list [{‘c’: 17, ‘b’: 8, ‘a’: 3}, {‘c’: 13, ‘b’: 12, ‘a’: 78}]

方法 #2：使用 lambda 和过滤器

# Python3 code to demonstrate
# filtering of list of dictionary
# on basis of condition
  
# initialising list of dictionary
ini_list = [{'a':1, 'b':3, 'c':7}, {'a':3, 'b':8, 'c':17},
            {'a':78, 'b':12, 'c':13}, {'a':2, 'b':2, 'c':2}]
  
# printing initial list of dictionary
print ("initial_list", str(ini_list))
  
# code to filter list
# where c is less than 10
res = list(filter(lambda x:x["c"] > 10, ini_list ))
  
# printing result
print ("resultant_list", str(res))

输出：

initial_list [{‘b’: 3, ‘c’: 7, ‘a’: 1}, {‘b’: 8, ‘c’: 17, ‘a’: 3}, {‘b’: 12, ‘c’: 13, ‘a’: 78}, {‘b’: 2, ‘c’: 2, ‘a’: 2}]
resultant_list [{‘c’: 17, ‘b’: 8, ‘a’: 3}, {‘c’: 13, ‘b’: 12, ‘a’: 78}]

方法#3：使用字典推导和列表推导

# Python3 code to demonstrate
# filtering of list of dictionary
# on basis of condition
  
# initialising list of dictionary
ini_list = [{'a':1, 'b':3, 'c':7}, {'a':3, 'b':8, 'c':17},
            {'a':78, 'b':12, 'c':13}, {'a':2, 'b':2, 'c':10}]
                  
# printing initial list of dictionary
print ("initial_list", str(ini_list))
  
# code to filter list
# where c is more than 10
  
res = [{ k:v for (k, v) in i.items()} 
        for i in ini_list if i.get('c') > 10]
  
# printing result
print ("resultant_list", str(res))

输出：

initial_list [{‘a’: 1, ‘c’: 7, ‘b’: 3}, {‘a’: 3, ‘c’: 17, ‘b’: 8}, {‘a’: 78, ‘c’: 13, ‘b’: 12}, {‘a’: 2, ‘c’: 10, ‘b’: 2}]
resultant_list [{‘a’: 3, ‘c’: 17, ‘b’: 8}, {‘a’: 78, ‘c’: 13, ‘b’: 12}]