python合并两个字典的方法总结

def merge(dict1, dict2):
    return(dict2.update(dict1))
# Driver code
dict1 = {'a': 10, 'b': 8}
dict2 = {'d': 6, 'c': 4}
# This returns None
print(merge(dict1, dict2))
# changes made in dict2
print(dict2)

def merge(dict1, dict2):
    res = {**dict1, **dict2}
    return res
# Driver code
dict1 = {'a': 10, 'b': 8}
dict2 = {'d': 6, 'c': 4}
dict3 = merge(dict1, dict2)
print(dict3)

def merge(dict1, dict2):
    res = dict1 | dict2
    return res
# Driver code
dict1 = {'x': 10, 'y': 8}
dict2 = {'a': 6, 'b': 4}
dict3 = merge(dict1, dict2)
print(dict3)

def merge(dict1, dict2):
    for i in dict2.keys():
        dict1[i]=dict2[i]
    return dict1
# Driver code
dict1 = {'x': 10, 'y': 8}
dict2 = {'a': 6, 'b': 4}
dict3 = merge(dict1, dict2)
print(dict3)

from collections import ChainMap
# create the dictionaries to be merged
dict1 = {'a': 1, 'b': 2}
dict2 = {'c': 3, 'd': 4}
# create a ChainMap with the dictionaries as elements
merged_dict = ChainMap(dict1, dict2)
# access and modify elements in the merged dictionary
print(merged_dict['a'])  # prints 1
print(merged_dict['c'])  # prints 3
merged_dict['c'] = 5  # updates value in dict2
print(merged_dict['c'])  # prints 5
# add a new key-value pair to the merged dictionary
merged_dict['e'] = 6  # updates dict1
print(merged_dict['e'])  # prints 6

def merge_dictionaries(dict1, dict2):
    merged_dict = dict1.copy()
    merged_dict.update(dict2)
    return merged_dict
# Driver code
dict1 = {'x': 10, 'y': 8}
dict2 = {'a': 6, 'b': 4}
print(merge_dictionaries(dict1, dict2))

# method to merge two dictionaries using the dict() constructor with the union operator (|)
def merge(dict1, dict2):
    # create a new dictionary by merging the items of the two dictionaries using the union operator (|)
    merged_dict = dict(dict1.items() | dict2.items())
    # return the merged dictionary
    return merged_dict
# Driver code
dict1 = {'a': 10, 'b': 8}
dict2 = {'d': 6, 'c': 4}
# merge the two dictionaries using the Merge() function
merged_dict = merge(dict1, dict2)
# print the merged dictionary
print(merged_dict)

from functools import reduce
def merge_dictionaries(dict1, dict2):
    merged_dict = dict1.copy()
    merged_dict.update(dict2)
    return merged_dict
dict1 = {'a': 10, 'b': 8}
dict2 = {'d': 6, 'c': 4}
dict_list = [dict1, dict2]  # Put the dictionaries into a list
result_dict = reduce(merge_dictionaries, dict_list)
print(result_dict)