improve algorithm (part 4):
improve algorithm (part 4):

- remove _fill_grid()
- fill grid_str within specs loop

plotly/python-api,plotly/python-api,ee-in/python-api,ee-in/python-api,plotly/plotly.py,plotly/plotly.py,ee-in/python-api,plotly/python-api,plotly/plotly.py