Quote: have main python script which calls other python scripts,

try:
		data = subprocess.check_output(cmd, shell=True, stderr=subprocess.STDOUT) 
		exitCode = 0
except subprocess.CalledProcessError as ex:
		data = ex.output
		data2 = ex.cmd
		exitCode = ex.returncode
		writeToAll(logfile, "Command:\n " + str(cmd) + "\nResult:\n Error occurred: " + str(data) + " exit code: " + str(exitCode) + "(0 for SUCCESS). Build will exit.", loggingLevel )
		writeInfoToLog( logfile, "---------------------------------------------------------------------------------------------")
		if exitOnError:
			exit(exitCode)
	if data[-1:] == '\n':
		data = data[:-1]
	return data, exitCode

#child.py
#!/usr/bin/env python

import sys
# 
print('Enter user:')
user = input()
print('Enter password:' )
passwd = input()
print('Enter tag:')
tag = input()

#Parent.py
...
p = subprocess.Popen([PYTHON, "-i", "./child.py"], stdout=subprocess.PIPE, stdin=subprocess.PIPE, shell=True)
(output, err) = p.communicate()
...

Quote:those are black box separated scripts.

import sys
from subprocess import (
    Popen, run, PIPE
    )

# running child process and wait until it has been finished
# this call blocks

print('Run the process and wait until the process finishes')
proc = run([sys.executable, 'child.py'], text=True, capture_output=True)
print(proc.stdout)

print('Run the process and do not wait until it has been finished')
# need to run Python in unbuffered mode, otherwise the data is buffered
# and you get the same result as before
proc = Popen([sys.executable, '-u' ,'child.py'], encoding='utf8', stdout=PIPE)

# proc.stdout is in TextMode and you can iterate over the lines
# you can do this with all files which are open in text mode, which is
# the default of open()
for line in proc.stdout:
    print(line)

import time

time.sleep(5)
print('Hello World')
time.sleep(5)
print('Quit child')

try:
data = subprocess.check_output(cmd, shell=True, stderr=subprocess.STDOUT) 
exitCode = 0
except subprocess.CalledProcessError as ex:
data = ex.output
data2 = ex.cmd
exitCode = ex.returncode
writeToAll(logfile, "Command:\n " + str(cmd) + "\nResult:\n Error occurred: " + str(data) + " exit code: " + str(exitCode) + "(0 for SUCCESS). Build will exit.", loggingLevel )
writeInfoToLog( logfile, "---------------------------------------------------------------------------------------------")
if exitOnError:
exit(exitCode)
if data[-1:] == '\n':
data = data[:-1]
return data, exitCode

#child.py
#!/usr/bin/env python

import sys
# 
print('Enter user:')
user = input()
print('Enter password:' )
passwd = input()
print('Enter tag:')
tag = input()

#Parent.py
...
p = subprocess.Popen([PYTHON, "-i", "./child.py"], stdout=subprocess.PIPE, stdin=subprocess.PIPE, shell=True)
(output, err) = p.communicate()

Quote: Don't know how to continue from here to pass the input parameters user inserted in child.py and received it in the parent.py and print it for example.

def get_user_data():
    user = input('User name: ')
    user_id = input('User id: ')
    return user, user_id

import child

user, user_id = child.get_user_data()
print('User {} has the id {}.'.format(user, user_id))

Output:
noisefloor@t450: python3 parent.py 
User name: noisefloor
User id: 666 
User noisefloor has the id 666.

Quote:I am just a python beginner, not an expert

from subprocess import Popen, PIPE
proc = Popen(['less'], stdin=PIPE, encoding='utf8')
proc.stdin.write('Hello World in less')
proc.stdin.flush()
proc.stdin.close()

from subprocess import Popen, PIPE
proc = Popen(['less'], stdin=PIPE, stdout=PIPE, encoding='utf8')
proc.stdin.write('Hello World in less from less')
proc.stdin.flush()
proc.stdin.close()
for line in proc.stdout:
    print(line)