how to add list value to dictionary to key if the key is already exists-CodePudding

I have a dictionary of all possible words(the keys) and its coordinates on a boggle game board(values).

I am writing a code in order to find all paths of a legal words on the board.

I created a new dictionary in order to contain only the legal words and path, so I want if there is a word with a couple paths I want to combine its to the same value of the word.

At first I a appending the first legal path so for example I have -

{"dog" : [(0,1),(0,2),(0,3)]}

now I have another path - [(1,0),(2,0),(3,0)] and I want the output to be-

{"dog" : [(0,1),(0,2),(0,3)],[(1,0),(2,0),(3,0)]}

I tried a few options but in all of them I get -

{"dog" : [(0,1),(0,2),(0,3),(1,0),(2,0),(3,0)]}

and it is not what I want. I would be happy for any help.

CodePudding user response：

You'll need to start with either an empty list or a list of lists, then append.

dictionary = {"dog" : []}
dictionary['dog'].append([(0,1),(0,2),(0,3)])
dictionary['dog'].append([(1,0),(2,0),(3,0)])

result:

{'dog': [[(0, 1), (0, 2), (0, 3)], [(1, 0), (2, 0), (3, 0)]]}

CodePudding user response：

A key can only hold one value. Your desire output is 2 values for one key. I think a nested array is what you want, it would look like this:

dict = {"dog" : [[(0,1),(0,2),(0,3)]]}
print("Initial dog paths: {}".format(dict["dog"]))

dict["dog"].append([(1,0),(2,0),(3,0)])
print("Final dog paths: {}".format(dict["dog"]))

output:

Initial dog paths: [[(0, 1), (0, 2), (0, 3)]]
Final dog paths: [[(0, 1), (0, 2), (0, 3)], [(1, 0), (2, 0), (3, 0)]]

CodePudding user response：

Dictionary can only have one value for each key. If you want to store multiple values, in this case, lists, you may try a list of list like:

{"dog" : [[(0,1),(0,2),(0,3)]]}

In such case, you can just append the path [(1,0),(2,0),(3,0)] to the outer list and the dictionary will become:

{"dog" : [[(0,1),(0,2),(0,3)],[(1,0),(2,0),(3,0)]]}

Hope this helps!