Typeerror: 'float' Object has no attribute 'getitem'

Question

First, as soon as the mouse is clicked, the shooting angle ( that is the same angle of the player) is stored in the bullets_array list. Second, it is given speed to the shot through the 'cos' and 'sin' and then limits its movement to at most 640px and 480px by the loop (so if it passes the shot it will be erased). Third, it is shown on the screen the shot in the position of the Player (player_x, player_y)

The shot was supposed to start at player_x, player_y, walk straight through the cosine and sine and then "die" at the screen limits.

But the following sentence is shown:

line 53
vel_x = Math.cos(Bullet[0])*10
Typeerror: 'float' Object has no attribute 'getitem'

Here is the code:

#
# Title: Shoot The Zombies
# Author(s): John Redbeard, ("http://john-redbeard.tumblr.com/")
# 

import pygame
from pygame.locals import *
import math

    # Initiate Pygame
pygame.init()
width, height = 640, 480
screen=pygame.display.set_mode((width, height))
pygame.display.set_caption("Shoot the Zombies")
fps = 60
fpsclock = pygame.time.Clock()

    # Load images
player = pygame.image.load("images/player.png")
player_x = 100
player_y = 100
posplayer_x = 0
posplayer_y = 0

grass = pygame.image.load("images/grass.png")

bullet = pygame.image.load("images/bullet.png")
bullets_array = []

target = pygame.image.load("images/target.png")

    # Main Loop Game
while True:

    pygame.mouse.set_visible(False)

    screen.fill(False)

    # Load on screen the grass in isometric way
    for x in range(width/grass.get_width()+1):
        for y in range(height/grass.get_height()+1):
            screen.blit(grass,(x*100,y*100))

    # Load on screen the rotated-positioned-player
    mouse_position = pygame.mouse.get_pos()
    angle = math.atan2(mouse_position[0] - player_x, mouse_position[1] - player_y)
    player_rotate = pygame.transform.rotate(player, 360+angle*57.29)
    player_position = (player_x - player_rotate.get_rect().width/2, player_y - player_rotate.get_rect().height/2)
    screen.blit(player_rotate, player_position)

    # load on screen the rotated-posioted-bullets
    for bullet in bullets_array:
        vel_x = math.cos(bullet[0])*10
        vel_y = math.sin(bullet[1])*10
        bullet[0] += vel_x
        bullet[1] += vel_y
        if bullet[0] >640 or bullet[1] > 480:
            bullets_array.remove(bullet)
        bullet1 = pygame.transform.rotate(bullet, 360+angle*57.29)
        screen.blit(bullet1, (player_x, player_y))

    # Load on screen the target
    screen.blit(target, (mouse_position))

    # Display window
    pygame.display.flip()

    # Run events
    for event in pygame.event.get():
        if event.type==pygame.QUIT:
            pygame.quit() 
            exit(False)

    # Event: W/A/S/D (Keyboard) moving player
        elif event.type == KEYDOWN:
            if event.key == K_w:
                posplayer_y -= 3
            elif event.key == K_a:
                posplayer_x -= 3
            elif event.key == K_s:
                posplayer_y += 3
            elif event.key == K_d:
                posplayer_x += 3

        elif event.type == KEYUP:
            if event.key == K_w:
                posplayer_y = 0
            elif event.key == K_a:
                posplayer_x = 0
            elif event.key == K_s:
                posplayer_y= 0
            elif event.key == K_d:
                posplayer_x = 0

    # Event: Mouse click shoot the bullet
        elif event.type == MOUSEBUTTONDOWN:
            bullets_array.append(math.atan2(mouse_position[0] - player_x, mouse_position[1] - player_y))

    player_x += posplayer_x
    player_y +=posplayer_y

    fpsclock.tick(fps)

Answer 1

The problem line is this:

bullets_array.append( math.atan2(mouse_position[0] - player_x, mouse_position[1] - player_y) )

In it you are adding a single float array. For the rest of your code, you probably intended to add a tuple array, type:

bullets_array.append(
    (
        math.atan2(mouse_position[0] - player_x, mouse_position[1] - player_y), 
        math.atan2( nao_sei_que_calculo_voce_quer_aqui )
    )
)

Either that or you continue to put floats in the array and replace bullet[0] and bullet[1] simply bullet. I didn’t stop to understand the logic and trigonometry of your algorithm to give the correct answer.

Answer 2

What types of elements bullet_array? That line:

bullets_array.append(math.atan2(mouse_position[0] - player_x, mouse_position[1] - player_y))

suggests they are simple numbers... The problem is that your code is giving error:

for bullet in bullets_array:
    vel_x = math.cos(bullet[0])*10

seems to expect that bullet be a list/tuple of numbers, and not a single number... But if this array contains simple numbers, as added by the first quoted snippet, then when trying to do:

bullet[0]

He complains that he can’t index a float (since floats do not have a method getitem).

See the correct type of elements bullets_array, and ensure that all your code is consistent with this.