new_contents: class Solution(object):
      def checkPossibility(self, nums):
          """
          :type nums: List[int]
          :rtype: bool
          """
          if not nums:
              return True
  
          l = len(nums)
          fixed = False
          for i in xrange(l):
              if i + 1 < l:
                  if nums[i] > nums[i + 1]:
                      if fixed:
                          return False
                      if i + 2 >= l or i == 0:
                          pass
                      elif nums[i + 1] >= nums[i - 1]:
                          pass
                      else:
                          nums[i + 1] = nums[i]
                      fixed = True
          return True
  
  
subject: Add py solution for 665. Non-decreasing Array