Python Matplotlib plot of RevokeArticle50 petition data

petition_time.csv

petition_time.py

import numpy as np
import pandas as pd
import seaborn as sns
from matplotlib import dates
import matplotlib.pyplot as plt

sns.set(style='darkgrid')

df = pd.read_csv('petition_time.csv',
                 parse_dates=[0])
df['Date'] = pd.to_datetime(df['Date'], format='%Y-%m-%d %H:%M:%S')
df['Value'] = df['Value'] / 1000

sample = 17
# Number of new signatures in the past 20 measurements
dy = (df['Value'].tail(sample).max() - df['Value'].tail(sample).min()) * 1000
# Time past during the past 20 measurements in seconds
dx = ((df['Date'].tail(sample).max() - df['Date'].tail(sample).min()) / np.timedelta64(1, 's'))
dx_hrs = ((df['Date'].tail(sample).max() - df['Date'].tail(sample).min()) / np.timedelta64(1, 'h'))

fig, ax = plt.subplots(figsize=(10,6))

ax.plot(df['Date'], df['Value'], marker='x', linewidth=0, markeredgewidth=1.5,
        markeredgecolor='k')

days = dates.DateFormatter('\n%d %b\n%Y')
hours = dates.DateFormatter('%H')

ax.xaxis.set_major_locator(dates.DayLocator())
ax.xaxis.set_minor_locator(dates.HourLocator())
ax.xaxis.set_major_formatter(days)
ax.xaxis.set_minor_formatter(hours)

ax.set_xlabel('Time (GMT)')
ax.set_ylabel('Number of signatures ($×10^3$)')

ax.set_xlim('2019-03-20 21:00', '2019-03-21 15:00')
ax.set_ylim(100, 1000)

ax.text('2019-03-21 00:00', 825,
        'Last {:.1f} hours, {:.0f} signatures per second'.format(dx_hrs, round(dy/dx, -1)),
        fontsize=18)

ax.grid(True, which='minor')

plt.savefig('petition_time.png')