How to run two python scripts in parallel on Windows - multithreading

Question

I currently have two python scripts, one is for writing data into a file and the other one is for reading data continuously from that file at the same time and do plotting. I want to create a third script which can automatically run these two scripts at the same time ( actually one slightly ahead of another because the file needs to be created for the other script to read from it).
So here is my code:
import serial
import sys
import Queue
import threading
import scipy.io
import numpy as num
from mpl_toolkits.mplot3d import *
import matplotlib.pyplot as plt
import numpy as np
from matplotlib import cm
import matplotlib.animation as animation
import time
from time import sleep
AngleText = open ("data2.txt" , "w") # open file for writing data
a= 1
b= 1
c =1
for x in range (0,20):
count = 0
sleep(0.5)
AngleText.writelines (str(a)+',')
AngleText.writelines (str(b)+',')
AngleText.writelines (str(c)+'\n')
count = count +1
a= a + 1
b= b + 2
c= c + 3
AngleText.flush()
And the plotting script:
from mpl_toolkits.mplot3d import *
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import time
import matplotlib
import threading as thrd
import numpy as np
fig = plt.figure()
ax = fig.add_subplot(111, projection = '3d')
def animate(i):
pullData = open ('data2.txt','r').read()
dataArray = pullData.split('\n')
xar = []
yar = []
zar = []
for eachLine in dataArray:
if len(eachLine)>1:
x,y,z = eachLine.split(',')
xar.append(float(x))
yar.append(float(y))
zar.append(float(z))
tx = xar.pop(0)
Floatx= float(tx)
ty = yar.pop(0)
Floaty= float(ty)
tz = zar.pop(0)
Floatz= float(tz)
x1 = [164, 94, 0, -100.5]
x2 = [164, 94, 0, -100.5]
y1= [-72.5, -103.5, -103.5, -134.5]
y2= [72.5, 103.5, 103.5, 134.5]
z1 = [112, 60, 3, 3]
z2 = [112, 60, 3, 3]
ax.plot(x1, y1, z1, color = 'b')
plt.hold(True)
ax.plot(x2, y2, z2, color = 'r')
plt.hold(True)
ax.scatter(Floatx, Floaty, Floatz)
plt.hold(False)
ani = animation.FuncAnimation(fig,animate, interval = 25)
ax.set_xlabel('x label')
ax.set_ylabel('y label')
ax.set_zlabel('z label')
plt.show()
Any advice would be appreciated!
My current solution is:
import os
from subprocess import *
import time
from time import sleep
p = Popen([r'testing.py'], shell=True, stdin=PIPE, stdout=PIPE)
output = p.communicate()
print output[0]
sleep(0.5)
#run child script 2
p = Popen([r'realPlot2.py'], shell=True, stdin=PIPE, stdout=PIPE)
output = p.communicate()
print output[0]
By running the above code, the graph won't be able to show until the writing function is finished.

Answer 1

use the multiprocessing class. you can start a new process to write to the file, then call p.join() to make the main function wait for the first process to finish, then start the second process. see here:
http://docs.python.org/2/library/multiprocessing.html