class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        g=len(nums)
        for i in range(0,len(nums)-1):
            index=nums[i]
            for j in range(0,g-1):
                if nums[j]==index:
                    g=g-1
                    nums.pop(j)  
        return g

I am getting error in 13th line