Go语言视频零基础入门到精通

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dict1={1:[1,11,111],2:[2,22,222]}
dict2={3:[3,33,333],4:[4,44,444]}
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]}
方法1：
dictMerged1=dict(dict1.items()+dict2.items())
方法2：
dictMerged2=dict(dict1, **dict2)
方法2等同于：
dictMerged=dict1.copy()
dictMerged.update(dict2)
或者
dictMerged=dict(dict1)
dictMerged.update(dict2)
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