Variable inside a while loop does not update the text outside of loop

Question

I am trying to create a small game. I made a score tracker with font.Font .

points = 0
score_text = pygame.font.Font('Pixeltype.ttf',100)
score_surf = score_text.render(f'Current points: {points}', None, 'Green')

This is before the while True loop that starts the game. This is pure variable declaration.

Later below, as i defeat 'enemies', I add +100 points to points.

Although my score does not update with screen.blit(score_surf,(850,40)), if i call print(points), my points have indeed increased.

I tried creating a separate text element for the points, still had this problem.

I am new to pygame module and i figured out I should practice the stuff i learned before moving on.

Thanks a lot in advance!

Updating `points` doesn't update `score_surf` automatically. There's no link between the rendered element and the variable. — Barmar, Feb 23 '22 at 20:01
This string: `f'Current points: {points}'` is evaluated immediately. — jarmod, Feb 23 '22 at 20:02
If you change `points` you have to render `score_surf` again. — Rabbid76, Feb 23 '22 at 20:03
How could i go about solving it? I tried to add screen.blit(score_surf, (850,40)) after every enemy elimination condition but i still have 0 points shown. — CallMeAdmiral, Feb 23 '22 at 20:07
As @Rabbid76 said: `score_surf` is still the same. You'll have to recreate it. — Matthias, Feb 23 '22 at 20:18

score 0 · Answer 1 · answered Feb 23 '22 at 20:10

The problem is in this line

score_surf = score_text.render(f'Current points: {points}', None, 'Green')

Expression f'Current points: {points}' gets evaluated only once to variable and passed to the render. It isn't function returning string but only formatted string.

You have to render score_surf again after it is changed.

How to fix it

See this answer.

Variable inside a while loop does not update the text outside of loop

1 Answers1

How to fix it