human
Solve in Python:
Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent.

A mapping of digit to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.


Example:

Input: "23"
Output: ["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].

Note:

Although the above answer is in lexicographical order, your answer could be in any order you want.

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Write me a the Python code you requested?
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#Here is the Python code you requested.

class Solution:
     def letterCombinations(self, digits):
         """
         :type digits: str
         :rtype: List[str]
         """
         interpret_digit = {
             '1': '',
             '2': 'abc',
             '3': 'def',
             '4': 'ghi',
             '5': 'jkl',
             '6': 'mno',
             '7': 'pqrs',
             '8': 'tuv',
             '9': 'wxyz',
             '0': ' '}
         all_combinations = [''] if digits else []
         for digit in digits:
             current_combinations = list()
             for letter in interpret_digit[digit]:
                 for combination in all_combinations:
                     current_combinations.append(combination + letter)
             all_combinations = current_combinations
         return all_combinations