如何分解嵌套字典以进行赋值迭代

Question

我有字典，我必须像这样迭代：

for akey,bdict in cdict.items():
    for dkey,edict in bdict.items():
        for fkey,gdict in edict.items():
            for hkey,ival in gdict.items():
                # do something

我如何定义explode，以便我可以使用任意大的嵌套字典来做这样的事情（我可能需要在一些迭代项周围加上括号，但括号的使用将由explode 决定，我会想象一下）？

for akey,dkey,fkey,hkey,ival in explode(cdict):
    # do something

# or 

for *keys,val in explode(any_nesteddict):
    # do something

7 月 9 日 23:38 popcorndude 回答后更新

有没有办法在字典中解压到某个级别，例如，如果我想得到akey、dkey 和edict？

for (akey,dkey),edict in explode(cdict, level=2):
    # do stuff

# which is different from original question:
for (akey,dkey,fkey,hkey),ival in explode(cdict):
    # do stuff

Answer 1

def explode(dct):
    # iterate over the top-level dictionary
    k, v in dct.items():
        if isinstance(v, dict):
            # it's a nested dictionary, so recurse
            for ks, v2 in explode(v):
                # ks is a tuple of keys, and we want to
                # prepend k, so we convert it into a tuple
                yield (k,)+ks, v2
        else:
            # make sure that in the base case
            # we're still yielding the keys as a tuple
            yield (k,), v

我们需要写(k,)而不仅仅是(k)，因为Python中的元组是用逗号定义的，而括号只是为了分组，所以(k) == k，但是(k,)是一个包含k的元组.