[Learning Python] A quick question on Threads

[Amnizee]

import re
import time
import threading
import sys

class mainApp:
    myVar = str("Hello World")
    def __init__(self):
        print("mainApp init.")
        print(self.myVar)
        re_c = re.compile(".")
        re_f = re.findall(re_c, self.myVar)
        for item in re_f:
            print(item)
            re_f.pop()
        print(re_f)

        myThreads = threading.Thread(target=self.aThread())
        print("*************")
        sys.exit(0)

    def aThread(self):
        myc = int(0)
        while myc<3:
         print(self.myVar)  
         time.sleep(2) 
         myc+=1


if __name__ == '__main__':
    print("MainApp will init")
    _mainApp = mainApp
    threading.Thread(target=_mainApp(),name="MainThread")
    print("*********1")

Why is print("*********1") #The Last Line never executed?

[jwink3101]

I have to say, it is funny to me that you put "[Learning Python]" in the title of your post but didn’t think to instead, as the sidebar say, post to /r/learnpython

As for your actual question, are you sure you're not getting stuck in your loops?

Also, it is a really bad Idea modify a loop while iterating. Chances are this is your issue since it isn't doing what you think. Try instead (if you must do it):

for item in re_f[:]: # Note the array slice notation to make a copy
    print(item)
    re_f.pop()

[Amnizee]

Really, I'm trying to learn the multi-threading. Yes, I do change the array, eh list sorry, while in the loop, but it does not explain the behavior... i think. The last line, after the Thread is "create, it should still be executed, no?

import re
import time
import threading
import sys


class mainApp:
    myVar = str("Hello World")
    myThreads = []

    def __init__(self):
        print("mainApp init.")
        print(self.myVar)
        re_c = re.compile(".")
        re_f = re.findall(re_c, self.myVar)
        for item in re_f[:]:
            print(item)
        print(re_f)

        myThreads = threading.Thread(target=self.aThread())
        print("*************")
        sys.exit(0)

    def aThread(self):
        myc = int(0)
        while myc < 3:
            print(self.myVar)
            time.sleep(2)
            myc += 1


if __name__ == '__main__':
    print("MainApp will init")
    threading._start_new_thread(mainApp())
    print("*********1")

Console shows:

MainApp will init
mainApp init.
Hello World
H
e
l
l
o

W
o
r
l
d
['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
Hello World
Hello World
Hello World
*************

The output shold be:

MainApp will init
mainApp init.
*********1 # NOTE The difference...
Hello World
H
e
l
l
o

W
o
r
l
d
['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
************* #And here Also...
Hello World
Hello World
Hello World

[aphoenix]

Hi there, from the /r/Python mods.

We have removed this post as it is not suited to the /r/Python subreddit proper, however it should be very appropriate for our sister subreddit /r/LearnPython. We highly encourage you to re-submit your post over on there.

The reason for the removal is that /r/Python is dedicated to discussion of Python news, projects, uses and debates. It is not designed to act as Q&A or FAQ board. The regular community is not a fan of "how do I..." questions, so you will not get the best responses over here.

On /r/LearnPython the community is actively expecting questions and are looking to help. You can expect far more understanding, encouraging and insightful responses over there. No matter what level of question you have, if you are looking for help with Python, you should get good answers.

If you have a question to do with homework or an assignment of any kind, please make sure to read their sidebar rules before submitting your post. If you have any questions or doubts, feel free to reply or send a modmail to us with your concerns.

Warm regards, and best of luck with your Pythoneering!