https://leetcode.com/problems/remove-duplicates-from-sorted-array/submissions/

removeDuplicates.py

def removeDuplicates(self, nums: List[int]) -> int:
        k = 0
        n = len(nums)
        for i in range(1, n):
            if nums[i] != nums[i - 1]:
                nums[k] = nums[i - 1]
                k += 1
        nums[k] = nums[n - 1]
        k += 1
        return k