如何判断字典中特定键的值是否是字典，以便我可以基于此递归解决编程问题？

Question

So I want to make sure that a particular value of key is a primitive data type ie not a dictionary. If it is a dictionary, I want to recursively check till I reach the end. ( base case-: no dictionary in the values) Let's say I have this code

dict ={ 
    "Roll No" : "1",
    "Car"     : {
         "Ferrari"  : "12",
         "Pontiac"  : "15"`
     },
     "Budget" : "3"
   }

How do I get "Car" as the key which has the datatype of the values to be a dictionary?

And how do I access the sub-dictionary ?

{ "Car":{
    "Ferrari":"12",
   "Pontiac":"15"
   },
} 

Answer 1

You can use python's type() function to decide if the element is a dictionary, and thus when to recurse:

searchDictionary( haystack, needle ):
    for key in haystack.keys():
        if type( haystack[key] ) is dict:
            searchDictionary( haystack[key], needle )
        elif type( haystack[key] ) is str:
            # TODO - match string
            if ( haystack[key] == needle ):
                print( "Found at "+str(key) )
        elif type( haystack[key] ) is int:
            # TODO - match integer
            pass

There's a bunch of other ways to iterate over the dictionary, but I chose this method to illustrate the answer in a readable manner.