def highlight_span(start=None, end=None, color='g', alpha=0.5, grapher=None):
"""
A quick shortcut way to highlight regions of a chart. Uses the Grapher.df.index
to translate non int-position arguments to int locations.
"""
if start is None and end is None:
raise Exception("strat and end cannot both be None")
if grapher is None:
fig = charting.gcf()
grapher = fig.grapher
df = grapher.df
if not df:
raise Exception("grapher/ax has no plots on it. Can only highlight populated ax")
if start is None:
start = 0
if end is None:
end = len(df.index)
# convert from object/string to pos-index
if not isinstance(start, int):
start = df.index.get_loc(start)
if not isinstance(end, int):
end = df.index.get_loc(end)
grapher.ax.axvspan(start, end, color=color, alpha=alpha)
def close_figures():
plt.close('all')
charting.gcf(reset=True)
