Python |将嵌套词典转换为扁平词典
原文:https://www . geesforgeks . org/python-convert-nested-dictionary-in-flatted-dictionary/
给定一个嵌套字典，任务是将该字典转换成一个扁平字典，在嵌套键启动的情况下，键用' _ '分隔。
下面给出了几个解决上述任务的方法。
方法#1:使用天真方法
Python 3
# Python code to demonstrate
# conversion of nested dictionary
# into flattened dictionary
# code to convert ini_dict to flattened dictionary
# default separator '_'
def flatten_dict(dd, separator ='_', prefix =''):
return { prefix + separator + k if prefix else k : v
for kk, vv in dd.items()
for k, v in flatten_dict(vv, separator, kk).items()
} if isinstance(dd, dict) else { prefix : dd }
# initialising_dictionary
ini_dict = {'geeks': {'Geeks': {'for': 7}},
'for': {'geeks': {'Geeks': 3}},
'Geeks': {'for': {'for': 1, 'geeks': 4}}}
# printing initial dictionary
print ("initial_dictionary", str(ini_dict))
# printing final dictionary
print ("final_dictionary", str(flatten_dict(ini_dict)))
Output: initial_dictionary {‘geeks’: {‘Geeks’: {‘for’: 7}}, ‘Geeks’: {‘for’: {‘geeks’: 4, ‘for’: 1}}, ‘for’: {‘geeks’: {‘Geeks’: 3}}} final_dictionary {‘Geeks_for_for’: 1, ‘geeks_Geeks_for’: 7, ‘for_geeks_Geeks’: 3, ‘Geeks_for_geeks’: 4}
方法 2:使用 相互解决问题
Python 3
# Python code to demonstrate
# conversion of nested dictionary
# into flattened dictionary
from collections import MutableMapping
# code to convert ini_dict to flattened dictionary
# default separator '_'
def convert_flatten(d, parent_key ='', sep ='_'):
items = []
for k, v in d.items():
new_key = parent_key + sep + k if parent_key else k
if isinstance(v, MutableMapping):
items.extend(convert_flatten(v, new_key, sep = sep).items())
else:
items.append((new_key, v))
return dict(items)
# initialising_dictionary
ini_dict = {'geeks': {'Geeks': {'for': 7}},
'for': {'geeks': {'Geeks': 3}},
'Geeks': {'for': {'for': 1, 'geeks': 4}}}
# printing initial dictionary
print ("initial_dictionary", str(ini_dict))
# printing final dictionary
print ("final_dictionary", str(convert_flatten(ini_dict)))
Output: initial_dictionary {‘Geeks’: {‘for’: {‘for’: 1, ‘geeks’: 4}}, ‘for’: {‘geeks’: {‘Geeks’: 3}}, ‘geeks’: {‘Geeks’: {‘for’: 7}}} final_dictionary {‘Geeks_for_geeks’: 4, ‘for_geeks_Geeks’: 3, ‘geeks_Geeks_for’: 7, ‘Geeks_for_for’: 1}
方法三:使用 Python 生成器
Python 3
# Python code to demonstrate
# conversion of nested dictionary
# into flattened dictionary
my_map = {"a" : 1,
"b" : {
"c": 2,
"d": 3,
"e": {
"f":4,
6:"a",
5:{"g" : 6},
"l":[1,"two"]
}
}}
# Expected Output
# {'a': 1, 'b_c': 2, 'b_d': 3, 'b_e_f': 4, 'b_e_6': 'a', 'b_e_5_g': 6, 'b_e_l': [1, 'two']}
ini_dict = {'geeks': {'Geeks': {'for': 7}},
'for': {'geeks': {'Geeks': 3}},
'Geeks': {'for': {'for': 1, 'geeks': 4}}}
# Expected Output
# {‘Geeks_for_geeks’: 4, ‘for_geeks_Geeks’: 3, ‘Geeks_for_for’: 1, ‘geeks_Geeks_for’: 7}
def flatten_dict(pyobj, keystring=''):
if type(pyobj) == dict:
keystring = keystring + '_' if keystring else keystring
for k in pyobj:
yield from flatten_dict(pyobj[k], keystring + str(k))
else:
yield keystring, pyobj
print("Input : %s\nOutput : %s\n\n" %
(my_map, { k:v for k,v in flatten_dict(my_map) }))
print("Input : %s\nOutput : %s\n\n" %
(ini_dict, { k:v for k,v in flatten_dict(ini_dict) }))
Output: initial_dictionary {‘for’: {‘geeks’: {‘Geeks’: 3}}, ‘geeks’: {‘Geeks’: {‘for’: 7}}, ‘Geeks’: {‘for’: {‘for’: 1, ‘geeks’: 4}}} final_dictionary {‘Geeks_for_geeks’: 4, ‘for_geeks_Geeks’: 3, ‘Geeks_for_for’: 1, ‘geeks_Geeks_for’: 7}
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