Python|展平给定的字典列表

给定字典列表，任务是将其转换为单个字典，即展平字典列表。

下面给出了一些解决给定任务的方法。

方法#1：使用朴素方法

Python3

# Python code to demonstrate
# to flatten list of dictionaries
  
# Initialising dictionary
ini_dict = [{'a':1}, {'b':2}, {'c':3}]
  
# printing initial dictionary
print ("initial dictionary", str(ini_dict))
  
# code to flatten list of dictionary
res = {}
for d in ini_dict:
    res.update(d)
      
# printing result
print ("result", str(res))

输出：

initial dictionary [{'a': 1}, {'b': 2}, {'c': 3}]
result {'b': 2, 'a': 1, 'c': 3}

方法 #2：使用 dict 理解

Python3

# Python code to demonstrate
# to flatten list of dictionaries
  
# Initialising dictionary
ini_dict = [{'a':1}, {'b':2}, {'c':3}]
  
# printing initial dictionary
print ("initial dictionary", str(ini_dict))
  
# code to flatten list of dictionary
res = {k: v for d in ini_dict for k, v in d.items()}
      
# printing result
print ("result", str(res))

输出：

initial dictionary [{'a': 1}, {'b': 2}, {'c': 3}]
result {'a': 1, 'c': 3, 'b': 2}

方法#3：使用reduce

Python3

# Python code to demonstrate
# to flatten list of dictionaries
from functools import reduce 
  
# Initialising dictionary
ini_dict = [{'a':1}, {'b':2}, {'c':3}]
  
# printing initial dictionary
print ("initial dictionary", str(ini_dict))
  
# code to flatten list of dictionary
res = reduce(lambda d, src: d.update(src) or d, ini_dict, {})
      
# printing result
print ("result", str(res))

输出：

initial dictionary [{'a': 1}, {'b': 2}, {'c': 3}]
result {'a': 1, 'c': 3, 'b': 2}

方法 #4：使用collections.ChainMap

Python3

# Python code to demonstrate
# to flatten list of 
# dictionaries
  
from collections import ChainMap
  
# Initialising dictionary
ini_dict = [{'a':1}, {'b':2}, {'c':3}]
  
# printing initial dictionary
print ("initial dictionary", str(ini_dict))
  
# code to flatten list of dictionary
res = ChainMap(*ini_dict)
      
# printing result
print ("result", str(res))

输出：

initial dictionary [{'a': 1}, {'b': 2}, {'c': 3}]
result ChainMap({'a': 1}, {'b': 2}, {'c': 3})