我需要合并多个字典,这是我有例如:
dict1 = {1:{"a":{A}}, 2:{"b":{B}}}
dict2 = {2:{"c":{C}}, 3:{"d":{D}}}
A、B、C和D是树的叶子,比如{"info1":"value", "info2":"value2"}
字典的级别(深度)未知,可能是{2:{"c":{"z":{"y":{c}}}}}
在我的例子中,它表示一个目录/文件结构,节点是文档,叶子是文件。
我想将它们合并得到:
dict3 = {1:{"a":{A}}, 2:{"b":{B},"c":{C}}, 3:{"d":{D}}}
我不确定如何用Python轻松做到这一点。
以下是来自@andrew cooke的回答。
它以更好的方式处理嵌套列表。
def deep_merge_lists(original, incoming):
"""
Deep merge two lists. Modifies original.
Recursively call deep merge on each correlated element of list.
If item type in both elements are
a. dict: Call deep_merge_dicts on both values.
b. list: Recursively call deep_merge_lists on both values.
c. any other type: Value is overridden.
d. conflicting types: Value is overridden.
If length of incoming list is more that of original then extra values are appended.
"""
common_length = min(len(original), len(incoming))
for idx in range(common_length):
if isinstance(original[idx], dict) and isinstance(incoming[idx], dict):
deep_merge_dicts(original[idx], incoming[idx])
elif isinstance(original[idx], list) and isinstance(incoming[idx], list):
deep_merge_lists(original[idx], incoming[idx])
else:
original[idx] = incoming[idx]
for idx in range(common_length, len(incoming)):
original.append(incoming[idx])
def deep_merge_dicts(original, incoming):
"""
Deep merge two dictionaries. Modifies original.
For key conflicts if both values are:
a. dict: Recursively call deep_merge_dicts on both values.
b. list: Call deep_merge_lists on both values.
c. any other type: Value is overridden.
d. conflicting types: Value is overridden.
"""
for key in incoming:
if key in original:
if isinstance(original[key], dict) and isinstance(incoming[key], dict):
deep_merge_dicts(original[key], incoming[key])
elif isinstance(original[key], list) and isinstance(incoming[key], list):
deep_merge_lists(original[key], incoming[key])
else:
original[key] = incoming[key]
else:
original[key] = incoming[key]
Short-n-sweet:
from collections.abc import MutableMapping as Map
def nested_update(d, v):
"""
Nested update of dict-like 'd' with dict-like 'v'.
"""
for key in v:
if key in d and isinstance(d[key], Map) and isinstance(v[key], Map):
nested_update(d[key], v[key])
else:
d[key] = v[key]
这类似于(并且构建在)Python的字典上。更新方法。它返回None(如果你喜欢,你总是可以添加返回d),因为它在原地更新dict d。v中的键将覆盖d中任何现有的键(它不会尝试解释字典的内容)。
它也适用于其他(“类字典”)映射。
这实际上是相当棘手的-特别是如果你想要一个有用的错误消息时,事情是不一致的,同时正确地接受重复但一致的条目(这是这里没有其他答案做的..)。
假设你没有大量的条目,递归函数是最简单的:
from functools import reduce
def merge(a, b, path=None):
"merges b into a"
if path is None: path = []
for key in b:
if key in a:
if isinstance(a[key], dict) and isinstance(b[key], dict):
merge(a[key], b[key], path + [str(key)])
elif a[key] == b[key]:
pass # same leaf value
else:
raise Exception('Conflict at %s' % '.'.join(path + [str(key)]))
else:
a[key] = b[key]
return a
# works
print(merge({1:{"a":"A"},2:{"b":"B"}}, {2:{"c":"C"},3:{"d":"D"}}))
# has conflict
merge({1:{"a":"A"},2:{"b":"B"}}, {1:{"a":"A"},2:{"b":"C"}})
注意,这会使a发生变化——b的内容被添加到a(也会返回a)。如果你想保留a,你可以叫它merge(dict(a) b)
Agf指出(下面),你可能有两个以上的字典,在这种情况下,你可以使用:
reduce(merge, [dict1, dict2, dict3...])
所有内容都将被添加到dict1中。
注意:我编辑了我的初始答案以改变第一个参数;这使得“reduce”更容易解释
基于@andrew cooke。这个版本处理字典的嵌套列表,还允许选项更新值
def merge(a, b, path=None, update=True):
"http://stackoverflow.com/questions/7204805/python-dictionaries-of-dictionaries-merge"
"merges b into a"
if path is None: path = []
for key in b:
if key in a:
if isinstance(a[key], dict) and isinstance(b[key], dict):
merge(a[key], b[key], path + [str(key)])
elif a[key] == b[key]:
pass # same leaf value
elif isinstance(a[key], list) and isinstance(b[key], list):
for idx, val in enumerate(b[key]):
a[key][idx] = merge(a[key][idx], b[key][idx], path + [str(key), str(idx)], update=update)
elif update:
a[key] = b[key]
else:
raise Exception('Conflict at %s' % '.'.join(path + [str(key)]))
else:
a[key] = b[key]
return a
我还没有对此进行广泛的测试,因此,鼓励您的反馈。
from collections import defaultdict
dict1 = defaultdict(list)
dict2= defaultdict(list)
dict3= defaultdict(list)
dict1= dict(zip(Keys[ ],values[ ]))
dict2 = dict(zip(Keys[ ],values[ ]))
def mergeDict(dict1, dict2):
dict3 = {**dict1, **dict2}
for key, value in dict3.items():
if key in dict1 and key in dict2:
dict3[key] = [value , dict1[key]]
return dict3
dict3 = mergeDict(dict1, dict2)
#sort keys alphabetically.
dict3.keys()
合并两个字典并添加公共键的值