import pygal from pygal.style import CleanStyle def ia_coverage_histogram(rows): """ Note: this returns a raw pygal chart; it does not render it to SVG/PNG """ raw_years = [int(r[0]) for r in rows] years = dict() for y in range(min(raw_years), max(raw_years)+1): years[int(y)] = dict(year=int(y), available=0, missing=0) for r in rows: if r[1]: years[int(r[0])]['available'] = r[2] else: years[int(r[0])]['missing'] = r[2] years = sorted(years.values(), key=lambda x: x['year']) CleanStyle.colors = ("green", "purple") label_count = len(years) if len(years) > 20: label_count = 10 chart = pygal.StackedBar(dynamic_print_values=True, style=CleanStyle, width=1000, height=500, x_labels_major_count=label_count, show_minor_x_labels=False) #chart.title = "Perpetual Access Coverage" chart.x_title = "Year" #chart.y_title = "Releases" chart.x_labels = [str(y['year']) for y in years] chart.add('Available', [y['available'] for y in years]) chart.add('Missing', [y['missing'] for y in years]) return chart