index out of range

[Deleted user]

pygame 1.9.6
Hello from the pygame community. https://www.pygame.org/contribute.html
Traceback (most recent call last):
File "/home/sarebjanjua/Documents/Code/PyGame/main.py", line 137, in
collision = isCollision(enemyX[i], enemyY[i], bulletX, bulletY)
IndexError: list index out of range