stop blinking numbers in pygame

Question

So what you were doing was essentially trying to draw something to the surface and then fill it, however you have to draw everything in the proper order so What I did is I changed the position of the for loop drawing all of the text to the screen as this still draws it, but should get rid of the weird blinking/flashing that you were experiencing.

import pygame
import time
import math
# Some config width height settings
canvas_width=1308
canvas_height=720
canvas_s=1004
# Just define some colors we can use
rojo=pygame.Color(255,0,0)
verde=pygame.Color(0,255,0)
azul=pygame.Color(0,0,255)
amarillo=pygame.Color(255,255,0,0)
marron=pygame.Color(85,65,0)
morado=pygame.Color(255,0,255)
naranja=pygame.Color(255,128,0)
lin=pygame.Color(255,255,255)
background_color=pygame.Color(0,0,0)

pygame.init()
#initialization of font module and creating a font to draw with
pygame.font.init()
fontdir = pygame.font.match_font('TimesNewRoman', False, False)
myfont = pygame.font.Font(fontdir,16)
# Set the window title
pygame.display.set_caption("Monitor Signos Vitales")
# Make a screen to see
screen=pygame.display.set_mode((canvas_width,canvas_height))
screen.fill(background_color)
# Make a surface to draw on
surface=pygame.Surface((canvas_width,canvas_s))
surface.fill(background_color)
#creating the random list and their corresponding surfaces
random_list = [random.randrange(0,1000) for x in range(5)]
text_list = [myfont.render(str(x),True,lin) for x in random_list]

# Simple main loop
running=True
while running:
    pos = (1220,0)
    for event in pygame.event.get():
        if event.type==pygame.QUIT:
            running=False

    # Redraw the background and some guide lines
    surface.fill(background_color)

    #--------------------------#
    #-------FIX POSITION-------#
    #--------------------------#
    for text in text_list:
        surface.blit(text,pos)
        pos = (pos[0],pos[1]+180)
    pygame.draw.line(surface, lin, (0, 90), (1004, 90))
    pygame.draw.line(surface, lin, (0, 180), (1004, 180))
    pygame.draw.line(surface, lin, (0, 270), (1004, 270))
    pygame.draw.line(surface, lin, (0, 360), (1004, 360))
    pygame.draw.line(surface, lin, (0, 450), (1004, 450))
    pygame.draw.line(surface, lin, (0, 540), (1004, 540))
    pygame.draw.line(surface, lin, (0, 630), (1004, 630))
    pygame.draw.line(surface, lin, (1004, 0), (1308, 720))
    pygame.draw.line(surface, lin, (1004, 180), (1308, 180))
    pygame.draw.line(surface, lin, (1004, 360), (1308, 360))
    pygame.draw.line(surface, lin, (1004, 540), (1308, 540))

    # Update sine wave
    frecuency=2;frecuency0=4;frecuency1=8;frecuency2=16;frecuency3=5;frecuency4=10
    frecuency5=15 
    amplitude=30 # in pixels
    speed=2
    for x0 in range(0,canvas_s):
        y0=int((canvas_height/2)+amplitude*math.sin(frecuency*((float(x0)/canvas_s)*    (2*math.pi)+(speed*time.time()))+270)-270)
        surface.set_at((x0,y0),amarillo)
    for x1 in range(0,canvas_s):
        y1=int((canvas_height/2)+amplitude*math.sin(frecuency0*((float(x1)/canvas_s)*(2*math.pi)+(speed*time.time()))+180)-180)
        surface.set_at((x1,y1),verde)
    for x2 in range(0,canvas_s):
        y2=int((canvas_height/2)+amplitude*math.sin(frecuency1*((float(x2)/canvas_s)*(2*math.pi)+(speed*time.time()))+90)-90)
        surface.set_at((x2,y2),naranja)
    for x3 in range(0,canvas_s):
        y3=int((canvas_height/2)+amplitude*math.sin(frecuency2*((float(x3)/canvas_s)*(2*math.pi)+(speed*time.time()))))
        surface.set_at((x3,y3),azul)
    for x4 in range(0,canvas_s):
        y4=int((canvas_height/2)+amplitude*math.sin(frecuency3*((float(x4)/canvas_s)*(2*math.pi)+(speed*time.time()))-90)+90)
        surface.set_at((x4,y4),rojo)
    for x5 in range(0,canvas_s):
        y5=int((canvas_height/2)+amplitude*math.sin(frecuency4*((float(x5)/canvas_s)*(2*math.pi)+(speed*time.time()))-180)+180)
        surface.set_at((x5,y5),marron)
    for x6 in range(0,canvas_s):
        y6=int((canvas_height/2)+amplitude*math.sin(frecuency5*((float(x6)/canvas_s)*(2*math.pi)+(speed*time.time()))-270)+270)
        surface.set_at((x6,y6),morado)

    # Put the surface we draw on, onto the screen
    screen.blit(surface,(0,0))
    # Show it.
    pygame.display.flip()