human
Can you provide a the Python code you requested given the following:
I found an interesting problem on https://leetcode.com/problems/count-numbers-with-unique-digits/:
Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x < 10n.

    Example:
Given n = 2, return 91. (The answer should be the total numbers in the range of 0 ≤ x < 100, excluding [11,22,33,44,55,66,77,88,99])

Credits:Special thanks to @memoryless for adding this problem and creating all test cases.

I tried it in Python, but could not do it. Can you solve it?
assistant
#Here is the Python code you requested.

class Solution:
     def countNumbersWithUniqueDigits(self, n):
         """
         :type n: int
         :rtype: int
         """
         if n ==0:
             return 1
         elif n == 1:
             return 10
         else:
             return (self.countNumbersWithUniqueDigits(n-1) - self.countNumbersWithUniqueDigits(n-2))*(11-n) + self.countNumbersWithUniqueDigits(n-1)