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]}
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
希望本文所述对大家的Python程序设计有所帮助。