字典扁平化

　　

source={'a':{'b':1,'c':2},'d':{'e':3,'f':{'g':4}}}
target={}
def flatmap(src,prefix=''):
    for k,v in src.items():
        if isinstance(v,(dict,)):
            flatmap(v,prefix=prefix+k+'~')
        else:
            target.setdefault(prefix+k,v)

flatmap(source)
print(target)

 

def flatmap(src,target=None,prefix=''):
    if target is None:
        target={}
    for k,v in src.items():
        if isinstance(v,(list,tuple,set,dict)):
            flatmap(v,target,prefix=prefix+k+'~')
        else:
            target.update(((prefix+k,v),))
    return target
print(flatmap(source))

def flatmap(src):
    def _flatmap(src,dst=None,prefix=''):
        if dst is None:
            dst={}
        for k,v in src.items():
            key=prefix+k
            if isinstance(v,(tuple,list,set,dict)):
                _flatmap(v,dst,key+'~')
            else:
                dst.update(((key,v),))
        return dst
    return _flatmap(src)
print(flatmap(source))