sample.py

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import serial
import platform
import time
import datetime
import csv
import re
print("Python version: " + platform.python_version())
print("matplotlib version: " + mpl.__version__)

fig, ax = plt.subplots()
line, = ax.plot(np.random.rand(10))
ax.set_ylim(-.1, .08)
xdata, ydata = [0]*100, [0]*100
SerialIn = serial.Serial("com4",115200)
FILE = open('Pressure ' + time.strftime("%Y-%m-%d %H:%M") + '.csv','a')

pattern = re.compile( r'([0-9 .+-]*)' ) #Added



def update(data):
    line.set_ydata(data)
    return line,

def run(data):
    global xdata, ydata
    x,y = data
    if (x == 0):
        xdata = [0]*100
        ydata = [0]*100
    del xdata[0]
    del ydata[0]
    xdata.append(x)
    ydata.append(y)
    line.set_data(xdata, ydata)
    return line,

def data_gen():
    x = 10
    while True:
        if (x >= 9):
            x = 0
        else:
            x += 0.1

        SerialIn.write(b"P\r")
        try:
            inRaw = re.search( pattern, 
SerialIn.read(SerialIn.in_waiting).decode('utf-8') ).group(0)
            inInt = float(inRaw)
            TIME = time.strftime('%H:%M:%S')
            FILE.write("{0},{1}\r".format(TIME, inInt))
            FILE.flush()
            print('['+time.strftime('%H:%M:%S')+']',inInt)
            time.sleep(1-time.time()%1)

        except:
           inInt = 0

        yield x, inInt

ani = animation.FuncAnimation(fig, run, data_gen, interval=0, blit=True)

plt.show()


SerialIn.close()
FILE.close()