RPi3 Utilisation Monitor / Sensor Plotter

import matplotlib
matplotlib.use('Agg')
from io import BytesIO
import base64
import matplotlib.pyplot as plt
import pandas as pd
import psutil
import seaborn as sns
from flask import Flask, render_template, request
from datetime import datetime
import time
from flask_socketio import SocketIO, emit

application = Flask(__name__)
application.config['SECRET_KEY'] = 'secret!'
socketio = SocketIO(application)

sns.set()
sns.set_context("paper")
sns.set_style("ticks", {'axes.facecolor': '#EAEAF2', 'axes.grid': True, 'grid.color': '.8', 'grid.linestyle': u'-'})
sns.set_palette("bright")
DataPointCount = 0
df = pd.DataFrame()
firstrequest = False
disconnectCount = 0
connecttime = time.time()

@socketio.on('connect', namespace='/')
def test_connect():
    global disconnectCount, connecttime
    disconnectCount = 0
    emit('my response', {'data': 'Connected'})
    connecttime = time.time()
    ip = request.environ['REMOTE_ADDR']
    print('{} connected    @ {}'.format(ip, datetime.now().strftime("%H:%M:%S on %d/%m/%y")))

@socketio.on('disconnect', namespace='/')
def test_disconnect():
    global disconnectCount, DataPointCount, firstrequest, df
    disconnectCount += 1
    ip = request.environ['REMOTE_ADDR']
    print('{} disconnected @ {}'.format(ip, datetime.now().strftime("%H:%M:%S on %d/%m/%y")))


@application.route('/')
def index():
    global width, DataPointCount, df, clock, startClock, firstrequest, connecttime
    width = 2
    if not firstrequest:
        firstrequest = True
        startClock = datetime.now()
        clock = datetime.now()

    while True:
        try:
            # If clock var is not equal to actual clock, run this...
            if clock != datetime.now():
                TD = datetime.now() - startClock
                CpuVal = psutil.cpu_percent(interval=None, percpu=False)
                RamVal = psutil.virtual_memory()[2]
                df2 = pd.DataFrame({'AvgCPU%': CpuVal, 'RAM%': RamVal,
                                    'Time':datetime.now().strftime("%S")},
                                   index=[DataPointCount])
                df = df.append(df2)
                df['meanCPU%'] = df['AvgCPU%'].mean()
                df['minCPU%'] = df['AvgCPU%'].min()
                df['maxCPU%'] = df['AvgCPU%'].max()
                df.set_index("Time", drop=True, inplace=True)

                if DataPointCount > 2:
                    plt.figure()
                    if DataPointCount % 500 == 0:
                        width = width / 1.3
                        if width < 0.5:
                            width = 0.5

                    df.plot(ylim=(0, 100), linewidth=width, alpha=0.5)
                    plt.Axes.set_autoscalex_on(plt, True)
                    plt.minorticks_off()
                    TD = str(TD)
                    plt.xlabel('Samples: {}'.format(DataPointCount))
                    plt.ylabel("% Utilisation")
                    TD = TD.split('.')[0]
                    plt.title("Time:\n{}".format(TD))
                    img_base64 = BytesIO()
                    plt.savefig(img_base64, format='png', dpi=120)
                    img = base64.b64encode(img_base64.getvalue())
                    img = str(img)
                    img = img[2:-1]
                    DataPointCount += 1
                    if time.time() - connecttime > 10:
                        DataPointCount = 0
                        firstrequest = False
                        df = pd.DataFrame()
                        connecttime = time.time()
                    plt.close('all')

                    return render_template('index.html', value=img)

                DataPointCount += 1
                plt.close('all')



        except(KeyboardInterrupt, SystemExit):
            return 0

if __name__ == '__main__':
    print('Server Up !')
    socketio.run(application, host='0.0.0.0', port=8000)