Python中实现两个字典（dict）合并的方法-Python Tutorial-php.cn

本文实例讲述了Python中实现两个字典（dict）合并的方法，分享给大家供大家参考。具体方法如下：

现有两个字典dict如下：

dict1={1:[1,11,111],2:[2,22,222]}
dict2={3:[3,33,333],4:[4,44,444]}

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合并两个字典得到类似：

{1:[1,11,111],2:[2,22,222],3:[3,33,333],4:[4,44,444]}

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方法1：

dictMerged1=dict(dict1.items()+dict2.items())

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方法2：

dictMerged2=dict(dict1, **dict2)

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方法2等同于：

dictMerged=dict1.copy()
dictMerged.update(dict2)

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或者：

dictMerged=dict(dict1)
dictMerged.update(dict2)

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方法2比方法1速度快很多，用timeit测试如下

$ python -m timeit -s 'dict1=dict2=dict((i,i) for i in range(100))' 'dictMerged1=dict(dict1.items()+dict2.items())'
  10000 loops, best of 3: 20.7 usec per loop
$ python -m timeit -s 'dict1=dict2=dict((i,i) for i in range(100))' 'dictMerged2=dict(dict1,**dict2)'
  100000 loops, best of 3: 6.94 usec per loop
$ python -m timeit -s 'dict1=dict2=dict((i,i) for i in range(100))' 'dictMerged3=dict(dict1)' 'dictMerged3.update(dict2)'
  100000 loops, best of 3: 7.09 usec per loop
$ python -m timeit -s 'dict1=dict2=dict((i,i) for i in range(100))' 'dictMerged4=dict1.copy()' 'dictMerged4.update(dict2)'
  100000 loops, best of 3: 6.73 usec per loop

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希望本文所述对大家的Python程序设计有所帮助。

Related labels：

python merge Dictionary

source：php.cn

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