How to get data in DateTime format from plot with Events in python?

Question

I have data in iPython DataFrame like this

    Date                        X           Y           Z
0   2015-11-30 20:23:05.556     281.764900          


        

Answer 1

Matplotlib's date support pre-dates numpy's datetime support (and predates pandas entirely). Therefore, it uses its own internal date convention.

To convert the "raw" number you're getting back to a datetime, use matplotlib.dates.num2date.

As an example similar to what you're doing:

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

import matplotlib.dates as mdates

def on_click(event):
    if event.inaxes is not None:
        print mdates.num2date(event.xdata)

t = pd.date_range('2015-11-01', '2016-01-06', freq='H')
y = np.random.normal(0, 1, t.size).cumsum()

df = pd.DataFrame({'Y':y}, index=t)

fig, ax = plt.subplots()
df.plot(ax=ax)
fig.canvas.mpl_connect('button_press_event', on_click)
plt.show()