python - Align rectangles on date axis -

i draw rectangle indicate range within x axis. can use locators setting ticks , labels, don't seem succeed using them draw rectangle. how go it?!

import datetime dt matplotlib import pyplot plt import matplotlib.dates dates  ddata = [dt.datetime.strptime('2010-02-05', "%y-%m-%d"),          dt.datetime.strptime('2010-02-19', "%y-%m-%d"),          dt.datetime.strptime('2010-03-05', "%y-%m-%d"),          dt.datetime.strptime('2010-03-19', "%y-%m-%d"),]  values = [123,678,987,345]  d1 = zip(ddata,values)  def nplot(data):      x = [date (date, value) in data]     y = [value (date, value) in data]  #     set stage     fig, ax = plt.subplots()     graph = fig.add_subplot(111)  #     plot data red line round markers     graph.plot(x,y,'r-o')      days   = dates.daylocator(interval=7)  # every week     months   = dates.monthlocator()  # every month  #     create locators , ticks     ax.xaxis.set_minor_locator(days)     ax.xaxis.set_minor_formatter(dates.dateformatter('%d'))      ax.xaxis.set_major_locator(months)     ax.xaxis.set_major_formatter(dates.dateformatter('\n\n%b'))     ax.xaxis.grid(true, which="major", linewidth=2)  #     how align rectangle specific dates?     gca().add_patch(rectangle((data[0][0], 1000),                      data[2][0], 1000, facecolor='w', alpha=0.9)) # doesn't work      plt.show()  nplot(d1) 

with set minor ticks

locs = ax.xaxis.get_minorticklocs() 

and write rectangle. odd, location of left side 6-digit float, location right side number of days since left side. no idea how works, seems to...

gca().add_patch(rectangle((locs[0], 0), 7, 1000, facecolor='w', alpha=0.9)) 

and wanted beginning: mark recurring ranges.

locs = ax.xaxis.get_minorticklocs() loc_len = len(locs) zloc = zip(locs, [7] * loc_len) # seven-day loops in zloc[::2]:     gca().add_patch(rectangle((i[0], 0), i[1], 1000, facecolor='w', alpha=0.9)) 

however, won't work if decide box months, each month has different number of days. @greg's suggestion of using fill_between option, set limits in relation data, not scale (which ok, guess):

xloc = zip(x[:-1], x[1:]) in xloc[::2]:     ax.fill_between(i, 0, 1200, facecolor='w', alpha=0.5) ylim(0, 1200) plt.show()