Returning value from a thread in python

Background

In this post we will see how python functions can be executed in a new thread and also how can we return some value from it.

NOTE : Python is pass by value similar to java. But for objects it is pass by value of the reference (again just like Java).

Returning value from a thread in python

Create a file called test.py and add the following code to it - 

import threading

print("Starting Test Python Modules");

def threadtarget(array):
    array.append("Hello World!")

array=[]
t = threading.Thread(target=threadtarget, args=(array,))
t.start()
t.join()
print("Value received from thread : " + array[0])
    
print("Terminating Test Python Module");

Explanation :  We are have a simple function threadtarget that accepts a list in it's argument and adds a String called "Hello World!" to it. In our script we are creating a new thread to run the method threadtarget and finally read the value of list we pass to confirm value added by thread to the list is retained.

Execute the script with -

• python test.py

This is captured in below screenshot

 Related Links

• Shutdown hook in Python(OSFG) 
• Capturing python output in a file along with the stdout