Python script that is able to receive and send input to another script interactively

I am trying to code a Python script that will execute another script and then interact with that script. By "interact" I mean send and receive input.

Here is how it should flow:

Script1 executes Script2 and waits for input from Script2.

Script1 receives input from Script 2 then sends back output to Script2.

This is repeated 2 or more times.

Lastly, I would like the whole process to be visible in the shell.

Here is the code I am feverishly trying to get to work:

import subprocess
from subprocess import Popen, PIPE, STDOUT

output1 = '1234'
output2 = '12345'
output3 = '123456'

p = subprocess.Popen(['receiver.py'], shell=True, stdout=subprocess.PIPE, stdin=subprocess.PIPE)

input1 = p.stdin.read()
print(input1)
p.stdin.write(output1)
p.communicate()[0]

input2 = p.stdin.read()
print(input2)
p.stdin.write(output2)
p.communicate()[0]

input3 = p.stdin.read()
print(input3)
p.stdin.write(output3)
p.communicate()[0]

p.stdin.close()
p.stdout.close()

quit()