在matplotlib中的x轴上绘制日期

Question

In the foll. plot, I want to plot dates on the x-axis. I have a list of dates:

import arrow as ar
date_plt = '2016-04-01'
_frst_day = '2016-01-01'
_last_day = '2016-12-31'
[ar.get(date_plt) + timedelta(days=x) for x in range((ar.get(_last_day) - ar.get(_frst_day)).days + 1)]

How can I plot dates on the x-axis while still being able to draw the line and the points on the plot (as shown)

Answer 1

I think you want (with some code to generate a fake plot):

labels=[ar.get(date_plt) + timedelta(days=x) for x in range((ar.get(_last_day)-ar.get(_frst_day)).days + 1)]
x=np.arange(366)
y=x*10
plt.plot([l.datetime for l in labels],y) #convert arrow in datetime

Note that doing this way the datetime objects are plotted and this are autmatically handled by matplotlib, for example in zoom and spacing adjustment (rather than for example plotting on x,y and replacing ticks). To plot or annotate your data, you can address directly to the datetime x axis, like (example day 150):

plt.plot(labels[150].datetime,y[150],'o')
plt.annotate('day 150',(labels[150].datetime,y[150]))