matplotlib string to dates

Question

Hi I am trying to convert a list of dates as strings to an x axis in matplotlib and I can\'t seem to get it to come out right.

dates =  [\'2014-05-06\', \'20         


        

Answer 1

Is this the goal? (Threw in rotation because it almost always comes up, with dates.)

datelist =  ['2014-05-06', '2014-05-07', '2014-05-08', '2014-05-09', '2014-05-10',    '2014-05-11', '2014-05-12', '2014-05-13']

import matplotlib
from matplotlib import pyplot
from matplotlib import dates
import datetime

converted_dates = list(map(datetime.datetime.strptime, datelist, len(datelist)*['%Y-%m-%d']))
x_axis = converted_dates
formatter = dates.DateFormatter('%Y-%m-%d')


y_axis = range(0,8)
pyplot.plot( x_axis, y_axis, '-' )
ax = pyplot.gcf().axes[0] 
ax.xaxis.set_major_formatter(formatter)
pyplot.gcf().autofmt_xdate(rotation=25)
pyplot.show()

Answer 2

The idea of using matplotlib.dates.datestr2num is in principle correct. You would then need to tell matplotlib to actually interprete the resulting numbers as dates. One easy option is to use plot_date instead of plot.

import matplotlib
import matplotlib.pyplot as plt
import matplotlib.dates

dates =  ['2014-05-06', '2014-05-07', '2014-05-08', '2014-05-09', 
          '2014-05-10', '2014-05-11', '2014-05-12', '2014-05-13']

converted_dates = matplotlib.dates.datestr2num(dates)
x_axis = (converted_dates)

y_axis = range(0,8)
plt.plot_date( x_axis, y_axis, '-' )

plt.show()

Answer 3

Try using strptime. Documentation is here: https://docs.python.org/2/library/datetime.html#strftime-strptime-behavior

For example:

import datetime
sDate = '2014-05-06'
dtDate = datetime.datetime.strptime(sDate,"%m-%d-%Y")

matplotlib can compare datetime objects.