code: def left_sections(self):
          
          lines = self.text.split('\n')
          sections = 0
  
          for i in range(len(lines)):
              if lines[i].startswith('+'):
                  sections += 1
          sections -= 1
  
          return sections
docs: The number of sections that touch the left side.
  
          During merging, the cell's text will grow to include other
          cells. This property keeps track of the number of sections that
          are touching the left side. For example::
  
                          +-----+-----+
              section --> | foo | dog | <-- section
                          +-----+-----+
              section --> | cat |
                          +-----+
  
          Has 2 sections on the left, but 1 on the right
  
          Returns
          -------
          sections : int
              The number of sections on the left