How to change the text when rendering in pygame code example

Example: how to render text in pygame

pygame.font.init() # you have to call this at the start, 
                   # if you want to use this module.
myfont = pygame.font.SysFont('Comic Sans MS', 30)

textsurface = myfont.render('Some Text', False, (0, 0, 0))

screen.blit(textsurface,(0,0))