Unique Word Abbreviation

The abbreviation of a word is a concatenation of its first letter, the number of characters between the first and last letter, and its last letter. If a word has only two characters, then it is an abbreviation of itself.

For example:

dog --> d1g because there is one letter between the first letter 'd' and the last letter 'g'.
internationalization --> i18n because there are 18 letters between the first letter 'i' and the last letter 'n'.
it --> it because any word with only two characters is an abbreviation of itself.

Implement the ValidWordAbbr class:

ValidWordAbbr(String[] dictionary) Initializes the object with a dictionary of words.
boolean isUnique(string word) Returns true if either of the following conditions are met (otherwise returns false):
- There is no word in dictionary whose abbreviation is equal to word's abbreviation.
- For any word in dictionary whose abbreviation is equal to word's abbreviation, that word and word are the same.

Example 1:

Input
["ValidWordAbbr", "isUnique", "isUnique", "isUnique", "isUnique", "isUnique"]
[[["deer", "door", "cake", "card"]], ["dear"], ["cart"], ["cane"], ["make"], ["cake"]]
Output
[null, false, true, false, true, true]

Explanation
ValidWordAbbr validWordAbbr = new ValidWordAbbr(["deer", "door", "cake", "card"]);
validWordAbbr.isUnique("dear"); // return false, dictionary word "deer" and word "dear" have the same abbreviation "d2r" but are not the same.
validWordAbbr.isUnique("cart"); // return true, no words in the dictionary have the abbreviation "c2t".
validWordAbbr.isUnique("cane"); // return false, dictionary word "cake" and word "cane" have the same abbreviation  "c2e" but are not the same.
validWordAbbr.isUnique("make"); // return true, no words in the dictionary have the abbreviation "m2e".
validWordAbbr.isUnique("cake"); // return true, because "cake" is already in the dictionary and no other word in the dictionary has "c2e" abbreviation.

Constraints:

1 <= dictionary.length <= 3 * 10⁴
1 <= dictionary[i].length <= 20
dictionary[i] consists of lowercase English letters.
1 <= word.length <= 20
word consists of lowercase English letters.
At most 5000 calls will be made to isUnique.

 class ValidWordAbbr:

    def __init__(self, dictionary: List[str]):
        self.d = {}

        for w in dictionary:
            abr = w if len(w) <= 2 else w[0] + str(len(w[1:-1])) + w[-1]    
            if abr in self.d and self.d[abr] != w:
                self.d[abr] = "-"
            else:
                self.d[abr] = w

    def isUnique(self, w: str) -> bool:
        abr = w if len(w) <= 2 else w[0] + str(len(w[1:-1])) + w[-1]  

        if abr not in self.d:
            return True
        elif self.d[abr] == w:
            return True
        return False


# Your ValidWordAbbr object will be instantiated and called as such:
# obj = ValidWordAbbr(dictionary)
# param_1 = obj.isUnique(word)

Unique Word Abbreviation

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