https://stackoverflow.com/questions/3232943/update-value-of-a-nested-dictionary-of-varying-depth
import copy
d = {‘k‘: ‘kv‘}
j_sc = {‘k1‘: copy.copy(d)}
j_dc = {‘k1‘: copy.deepcopy(d)}
jc = {‘k1‘: d.copy()}
k = {‘k1‘: d}
d = {‘j‘: ‘jv‘}
https://stackoverflow.com/questions/3232943/update-value-of-a-nested-dictionary-of-varying-depth
原文：https://www.cnblogs.com/yuanjiangw/p/11917367.html