Both Ways / Reverse search on dictionary Python

Question

I just want to complement this answer on how to search a dictionary in both ways.

My answer includes a init method to initialize the TwoWayDict class with a already existing dictionary.

Answer 1

Here it is:

class TwoWayDict(dict):
    def __init__(self, init_dict):
        
        for key, value in init_dict.items():
            dict.__setitem__(self, key, value)
            dict.__setitem__(self, value, key)
 
    def __setitem__(self, key, value):
        # Remove any previous connections with these values
        if key in self:
            del self[key]
        if value in self:
            del self[value]
        dict.__setitem__(self, key, value)
        dict.__setitem__(self, value, key)

    def __delitem__(self, key):
        dict.__delitem__(self, self[key])
        dict.__delitem__(self, key)

    def __len__(self):
        """Returns the number of connections"""
        return dict.__len__(self) // 2

So now you can initialize a TwoWayDict using a already existenting dictionary.

Have a nice day ^^