How can I made a string that is updated by a thread reflect the changes on Python's curses?

-1

I am planning to implement the curses library into an existing Python script for a client. The script will be run purely through SSH.

I am currently attempting to simulate some of the output that my script would generate.

In my 'testing-the-waters' script I have 3 variables: x, y, z.

I have a thread running alongside the curses loop that increments x, y, and z every x seconds. In the loop I am simply printing the three variables to the terminal screen.

The problem: The variables do not update until I provide some kind of input.
How can I make the terminal string update the values automagically?

I am testing this on a Terminal on Kubuntu. I tried Urwid and ran into a similar problem.

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True





def increment_ints():

    global x, y, z

    while go:

        x += 1

        y += 2

        z += 3

        time.sleep(3)





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False





if __name__ == '__main__':

    t = Thread(target=update_ints)

    t.setDaemon(True)

    t.start()

    curses.wrapper(main)

Expected:
The values of x, y, and z are displayed and reflect the increments without input.

Actual results:
The values of x, y, and z remain 1, 2, and 3 respectively and updates only when I press a key.

-----------Edit:
This works as expected:

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True

def update_ints():

    global x, y, z

    x += 1

    y += 2

    z += 3





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        update_ints()

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False

        time.sleep(3)





if __name__ == '__main__':

    curses.wrapper(main)

But I will need the values to be updated from a thread.

edited Jan 3 at 8:27

asked Jan 3 at 8:00

CoreCreatives

1245

1

Why def increment_ints(): but t = Thread(target=update_ints)?

– NEGR KITAEC
Jan 3 at 8:07

Thanks for the quick response! I am simulating my other script's infrastructure - it updates values from a thread and I want the displayed text to reflect the updated values.

– CoreCreatives
Jan 3 at 8:13

Does it work as expected if you replace curses calls with input and print?

– NEGR KITAEC
Jan 3 at 8:17

Yes. That would print each x: {x}, y = {y}, z = {z} line by line, but the desired input is one static screen with the values updated in place.

– CoreCreatives
Jan 3 at 8:20

1

Well you have to look into source code of screen.getch() then

– NEGR KITAEC
Jan 3 at 8:26

|
show 1 more comment

-1

I am planning to implement the curses library into an existing Python script for a client. The script will be run purely through SSH.

I am currently attempting to simulate some of the output that my script would generate.

In my 'testing-the-waters' script I have 3 variables: x, y, z.

I have a thread running alongside the curses loop that increments x, y, and z every x seconds. In the loop I am simply printing the three variables to the terminal screen.

The problem: The variables do not update until I provide some kind of input.
How can I make the terminal string update the values automagically?

I am testing this on a Terminal on Kubuntu. I tried Urwid and ran into a similar problem.

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True





def increment_ints():

    global x, y, z

    while go:

        x += 1

        y += 2

        z += 3

        time.sleep(3)





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False





if __name__ == '__main__':

    t = Thread(target=update_ints)

    t.setDaemon(True)

    t.start()

    curses.wrapper(main)

Expected:
The values of x, y, and z are displayed and reflect the increments without input.

Actual results:
The values of x, y, and z remain 1, 2, and 3 respectively and updates only when I press a key.

-----------Edit:
This works as expected:

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True

def update_ints():

    global x, y, z

    x += 1

    y += 2

    z += 3





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        update_ints()

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False

        time.sleep(3)





if __name__ == '__main__':

    curses.wrapper(main)

But I will need the values to be updated from a thread.

edited Jan 3 at 8:27

asked Jan 3 at 8:00

CoreCreatives

1245

1

Why def increment_ints(): but t = Thread(target=update_ints)?

– NEGR KITAEC
Jan 3 at 8:07

Thanks for the quick response! I am simulating my other script's infrastructure - it updates values from a thread and I want the displayed text to reflect the updated values.

– CoreCreatives
Jan 3 at 8:13

Does it work as expected if you replace curses calls with input and print?

– NEGR KITAEC
Jan 3 at 8:17

Yes. That would print each x: {x}, y = {y}, z = {z} line by line, but the desired input is one static screen with the values updated in place.

– CoreCreatives
Jan 3 at 8:20

1

Well you have to look into source code of screen.getch() then

– NEGR KITAEC
Jan 3 at 8:26

|
show 1 more comment

-1

I am planning to implement the curses library into an existing Python script for a client. The script will be run purely through SSH.

I am currently attempting to simulate some of the output that my script would generate.

In my 'testing-the-waters' script I have 3 variables: x, y, z.

I have a thread running alongside the curses loop that increments x, y, and z every x seconds. In the loop I am simply printing the three variables to the terminal screen.

The problem: The variables do not update until I provide some kind of input.
How can I make the terminal string update the values automagically?

I am testing this on a Terminal on Kubuntu. I tried Urwid and ran into a similar problem.

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True





def increment_ints():

    global x, y, z

    while go:

        x += 1

        y += 2

        z += 3

        time.sleep(3)





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False





if __name__ == '__main__':

    t = Thread(target=update_ints)

    t.setDaemon(True)

    t.start()

    curses.wrapper(main)

Expected:
The values of x, y, and z are displayed and reflect the increments without input.

Actual results:
The values of x, y, and z remain 1, 2, and 3 respectively and updates only when I press a key.

-----------Edit:
This works as expected:

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True

def update_ints():

    global x, y, z

    x += 1

    y += 2

    z += 3





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        update_ints()

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False

        time.sleep(3)





if __name__ == '__main__':

    curses.wrapper(main)

But I will need the values to be updated from a thread.

edited Jan 3 at 8:27

asked Jan 3 at 8:00

CoreCreatives

1245

I am planning to implement the curses library into an existing Python script for a client. The script will be run purely through SSH.

I am currently attempting to simulate some of the output that my script would generate.

In my 'testing-the-waters' script I have 3 variables: x, y, z.

I have a thread running alongside the curses loop that increments x, y, and z every x seconds. In the loop I am simply printing the three variables to the terminal screen.

The problem: The variables do not update until I provide some kind of input.
How can I make the terminal string update the values automagically?

I am testing this on a Terminal on Kubuntu. I tried Urwid and ran into a similar problem.

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True





def increment_ints():

    global x, y, z

    while go:

        x += 1

        y += 2

        z += 3

        time.sleep(3)





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False





if __name__ == '__main__':

    t = Thread(target=update_ints)

    t.setDaemon(True)

    t.start()

    curses.wrapper(main)

Expected:
The values of x, y, and z are displayed and reflect the increments without input.

Actual results:
The values of x, y, and z remain 1, 2, and 3 respectively and updates only when I press a key.

-----------Edit:
This works as expected:

import curses

import time

from threading import Thread



x, y, z = 0, 0, 0

go = True

def update_ints():

    global x, y, z

    x += 1

    y += 2

    z += 3





def main(screen):

    global go

    curses.initscr()

    screen.clear()

    while go:

        update_ints()

        screen.addstr(0, 0, f"x: {x}, y = {y}, z = {z}")

        c = screen.getch()

        if c == ord('q'):

            go = False

        time.sleep(3)





if __name__ == '__main__':

    curses.wrapper(main)

But I will need the values to be updated from a thread.

python terminal curses

edited Jan 3 at 8:27

asked Jan 3 at 8:00

CoreCreatives

1245

edited Jan 3 at 8:27

asked Jan 3 at 8:00

CoreCreatives

1245

edited Jan 3 at 8:27

asked Jan 3 at 8:00

CoreCreatives

1245

asked Jan 3 at 8:00

CoreCreatives

1245

asked Jan 3 at 8:00

CoreCreatives

1245

1

Why def increment_ints(): but t = Thread(target=update_ints)?

– NEGR KITAEC
Jan 3 at 8:07

Thanks for the quick response! I am simulating my other script's infrastructure - it updates values from a thread and I want the displayed text to reflect the updated values.

– CoreCreatives
Jan 3 at 8:13

Does it work as expected if you replace curses calls with input and print?

– NEGR KITAEC
Jan 3 at 8:17

Yes. That would print each x: {x}, y = {y}, z = {z} line by line, but the desired input is one static screen with the values updated in place.

– CoreCreatives
Jan 3 at 8:20

1

Well you have to look into source code of screen.getch() then

– NEGR KITAEC
Jan 3 at 8:26

|
show 1 more comment

1

Why def increment_ints(): but t = Thread(target=update_ints)?

– NEGR KITAEC
Jan 3 at 8:07

Thanks for the quick response! I am simulating my other script's infrastructure - it updates values from a thread and I want the displayed text to reflect the updated values.

– CoreCreatives
Jan 3 at 8:13

Does it work as expected if you replace curses calls with input and print?

– NEGR KITAEC
Jan 3 at 8:17

Yes. That would print each x: {x}, y = {y}, z = {z} line by line, but the desired input is one static screen with the values updated in place.

– CoreCreatives
Jan 3 at 8:20

1

Well you have to look into source code of screen.getch() then

– NEGR KITAEC
Jan 3 at 8:26

Why def increment_ints(): but t = Thread(target=update_ints)?

– NEGR KITAEC
Jan 3 at 8:07

Thanks for the quick response! I am simulating my other script's infrastructure - it updates values from a thread and I want the displayed text to reflect the updated values.

– CoreCreatives
Jan 3 at 8:13

Does it work as expected if you replace curses calls with input and print?

– NEGR KITAEC
Jan 3 at 8:17

Yes. That would print each x: {x}, y = {y}, z = {z} line by line, but the desired input is one static screen with the values updated in place.

– CoreCreatives
Jan 3 at 8:20

Well you have to look into source code of screen.getch() then

– NEGR KITAEC
Jan 3 at 8:26

|
show 1 more comment

1 Answer
1

active

oldest

votes

The issue was that c = screen.getch() was blocking the loop and preventing the values from being updated.

Removing...

c = screen.getch()

if c == ord('q'):

   go = False

... produced the intended results.

Thank you NEGR KITAEC

answered Jan 3 at 8:39

CoreCreatives

1245

add a comment |

Your Answer

StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54018395%2fhow-can-i-made-a-string-that-is-updated-by-a-thread-reflect-the-changes-on-pytho%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

The issue was that c = screen.getch() was blocking the loop and preventing the values from being updated.

Removing...

c = screen.getch()

if c == ord('q'):

   go = False

... produced the intended results.

Thank you NEGR KITAEC

answered Jan 3 at 8:39

CoreCreatives

1245

add a comment |

The issue was that c = screen.getch() was blocking the loop and preventing the values from being updated.

Removing...

c = screen.getch()

if c == ord('q'):

   go = False

... produced the intended results.

Thank you NEGR KITAEC

answered Jan 3 at 8:39

CoreCreatives

1245

add a comment |

The issue was that c = screen.getch() was blocking the loop and preventing the values from being updated.

Removing...

c = screen.getch()

if c == ord('q'):

   go = False

... produced the intended results.

Thank you NEGR KITAEC

answered Jan 3 at 8:39

CoreCreatives

1245

The issue was that c = screen.getch() was blocking the loop and preventing the values from being updated.

Removing...

c = screen.getch()

if c == ord('q'):

   go = False

... produced the intended results.

Thank you NEGR KITAEC

answered Jan 3 at 8:39

CoreCreatives

1245

answered Jan 3 at 8:39

CoreCreatives

1245

answered Jan 3 at 8:39

CoreCreatives

1245

answered Jan 3 at 8:39

CoreCreatives

1245

add a comment |

draft saved

draft discarded

Thanks for contributing an answer to Stack Overflow!

Please be sure to answer the question. Provide details and share your research!

But avoid …

Asking for help, clarification, or responding to other answers.

Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

搜尋此網誌

Bdtjtk