I'm having another problem with the game I'm making, I want the Asteroids sprite to be randomized every time I new asteroid is created by the spawner class, but I keep getting this error 'non-default argument follows default argument', and I'm pretty much stumped on what to do, The actual randomized image is stored inside the spawner and is then imported to the Asteroid class. Any help would be greatly appreciated, the images list is a global variable.
images = [games.load_image("asteroid_small.bmp"),
games.load_image("asteroid_med.bmp"),
games.load_image("asteroid_big.bmp")]
def check_drop(self):
""" Decrease countdown or drop asteroid and reset countdown. """
if self.time_til_drop > 0:
self.time_til_drop -= 0.7
else:
asteroid_size = random.choice(images)
new_asteroid = Asteroid(x = self.x,image = asteroid_size)
games.screen.add(new_asteroid)
And then this is the part of the asteroid class that the randomized image will be stored in
def __init__(self, x, y = 10,image):
""" Initialize a asteroid object. """
super(Asteroid, self).__init__(image = image,
x = x, y = y,
dy = Asteroid.speed)
Your problem isn't with how you instantiate the asteroid, it is how you define it:
def __init__(self, x, y = 10,image):
If you look, image is last, after y, which has a default argument. In Python you cannot do such things. You have two options:
def __init__(self, x, y = 10, image = None):
# default the argument to some sentinel value
# Test for sentinel and the reassign if not matched.
image = image if image else random.choice(images)
or
def __init__(self, x, image, y = 10):
# re-order your arguments.
# Also note that image, x, y might be a better order
# (#see comment by Micael0x2a)
Related
I have got the tile class:
class Tile:
tile_pref = {
"sprites": []
}
pos = Vector2(vector_zero)
def img(self, x, y, tilemap, t):
return self.tile_pref["sprites"][0]
def __init__(self, img, pos):
self.tile_pref["sprites"].append(img)
self.pos = pos
And another part, cropped:
src is valid string path, spacing, tile_size, offset are vectors with .x and .y.
self.__tiles__ is array.
img = pyglet.image.load(src)
for i in range((img.height - offset.x) // (spacing.x + tile_size.x) + 1):
for j in range((img.width - offset.y) // (spacing.y + tile_size.y) + 1):
a = offset.x + (tile_size.x + spacing.x) * j
b = offset.y + (tile_size.y + spacing.y) * i
self.__tiles__.append(Tile(img.get_region(a, b, tile_size.x, tile_size.y), Vector2(i, j)))
Main problem is in what tile_pref["sprites"] is not 1 in length, bu equals to all amount of tiles. How can I fix it?
I think, when I call img.get_region, it returns me a link to it. So, it calls append any time link is changing.
Here:
class Tile:
tile_pref = {
"sprites": []
}
pos = Vector2(vector_zero)
You are defining tile_pref and pos as class attributes - attributes that belong to the class (not to the instances of...), and are shared amongst all instances. Unless shadowed by an instance attribute, class attributes are also available thru the instance (which is how you can access methods, which ARE class attributes), so here:
def __init__(self, img, pos):
self.tile_pref["sprites"].append(img)
you are actually mutating the class's own tile_pref attribute - so whatever you add here will be visible to all instances.
Note that the following line:
self.pos = pos
creates a 'pos' instance attribute (you are binding the name, not mutating), which will shadow the class attribute.
For what it's worth, all this is clearly and explicitely documented in the official tutorial - so I kindly suggest you stop what you're doing, take a day (or two if needed) to do the whole tutorial, then come back to your code. This will save you a lot of time and pain and frustration.
Not sure I am even asking the question correctly, but I will explain. I have created a class, and I have created instances in that class, the problem is I want to be able to use an instance which is chosen by the user via input. Let's say I would like to create a chess game. I want to be able to move a piece forward (possibly backward), left, and right. Suppose I have already created a method inside the class to move the piece and each piece has a name, x-coord, and y-coord. This is the issue I get
class Piece(object):
def __init__(self, x , y):
self.x = x
self.y = y
def move(self, amount, direction):
if direction == 'right':
self.x = self.x + amount
if direction == 'left':
self.x = self.x - amount
if direction == 'up':
self.y = self.y + amount
if direction == 'down':
self.y = self.y - amount
rook = Piece(0,0)
piece = input('What piece would you like to move?')
#Assume that the user types rook after this prompt
piece.move(4,'right')
Now I get an error because the input which is assigned to the variable piece is a string, and when I need rook.move, I am actually getting 'rook'.move
I understand variables can be changed using int(var), float(var), str(var), but how would one go about changing a variable to a class variable.
A way would be to have a dictionary that maps the piece names to your classes.
So
pieces = {
'Queen': Piece(0,0),
'Tower': Piece(0,0),
'Rook' Piece(0,0)
}
inp = input('Which piece would you like to move?')
if inp in pieces:
pieces[inp]().move(4, right)
else:
print('No such piece: %s - Valid pieces: %s' % (inp, pieces.keys()))
I'm working under python pyramid, with Python3.
I have a model that looks like this:
class OneTimeCode(Base):
__tablename__ = 'otc_one_time_codes'
otc_one_time_code_id = Column(Integer, primary_key=True)
otc_one_time_code = Column(String(32))
otc_usr_user_id = Column(Integer, ForeignKey('usr_users.usr_user_id'), nullable=True)
otc_expire_time = Column(DateTime)
def __init__(self, otc_usr_user_id, otc_expire_time=None):
self.otc_usr_user_id = otc_usr_user_id
if otc_expire_time is None:
self.otc_expire_time = (datetime.now() + timedelta(6*365/12)).isoformat()
else:
self.otc_expire_time = otc_expire_time
#classmethod
def get_code(self, hlength=6):
seed = datetime.now() + timedelta(random.randrange(1,10000))
tmp_hash = hashlib.md5(seed.strftime("%Y-%m-%d %H:%M:%S.%F").encode('utf-8')).hexdigest()
if hlength == 32:
self.otc_one_time_code = tmp_hash
else:
self.otc_one_time_code = tmp_hash[0 : hlength]
print(self.otc_one_time_code)
The problem is, when I instantiate one of these objects and then explicitly call get_code, the print line at the end prints to the screen the code successfully.
However, in my view, if I explicitly try to print that property, it's 'None'
Here's what my view code looks like:
otc = OneTimeCode(
otc_usr_user_id = user.usr_user_id
)
otc.get_code()
pprint.pprint(vars(otc))
session.add(otc)
And the console output looks like this:
0d097c
{'_sa_instance_state': <sqlalchemy.orm.state.InstanceState object at 0x50877d0>, 'otc_expire_time': '2015-02-13T10:56:14.244447', 'otc_usr_user_id': 1} 2014-08-14 22:56:14,245
INFO [sqlalchemy.engine.base.Engine][Dummy-2] INSERT INTO otc_one_time_codes (otc_one_time_code, otc_usr_user_id, otc_expire_time) VALUES (%(otc_one_time_code)s, %(otc_usr_user_id)s, %(otc_expire_time)s) RETURNING otc_one_time_codes.otc_one_time_code_id 2014-08-14 22:56:14,245
INFO [sqlalchemy.engine.base.Engine][Dummy-2] {'otc_one_time_code': None, 'otc_expire_time': '2015-02-13T10:56:14.244447', 'otc_usr_user_id': 1} 2014-08-14 22:56:14,247
INFO [sqlalchemy.engine.base.Engine][Dummy-2] COMMIT
You can see the value inside the model: 0d097c, and also the pprint object, where it doesn't look like the property exists.
Why can't I get access to this property?
Looks like you should be using a #property instead of a OTC, however it also seems like this may be something you DON'T want to calculate each time!
# for all the docstrings, let multi = Multi(2)
class Multi(object):
def __init__(self, attribute):
"""When instantiated, set self.attribute to attribute"""
self.attribute = attribute
#property
def attribute_times_ten(self):
"""accessed via multi.attribute_times_ten
and will return 20. Use properties to signify
a variable that requires some work done to it
that needs to calculated each time it's called."""
return attribute_times_ten
#classmethod
def times_ten(cls, num):
"""Not the best example, but a #classmethod will
give the class as its first argument, NOT the
instance. This is useful in lots of constructor
settings, e.g. CreateClass.fromstring("attributes")"""
return num * 5
def generate_number(self, multiplier):
"""This is just a normal method. This is what I think
you want, tbh, and you should probably call it in your
__init__ method since you NEED this to run in your OTC
for it to work as intended. Methods (like properties)
are automagically passed the instance as the first
argument, so we can CHANGE self.attribute with that."""
self.attribute = self.attribute * multiplier
Docstrings should be self descriptive, but:
multi = Multi(2)
multi.attribute_times_ten # returns 20
Multi.times_ten(8) # returns 80, note the capital M!
multi.generate_number(3) # self.attribute is now 6
multi.attribute_times_ten # returns 60
A real-world case where you might need all of the above:
class _Tile(object):
def __init__(self, x, y):
"""A naive implementation of Tile that doesn't care
what its side length is and doesn't have any properties
to hide its attributes"""
self.x = x
self.y = y
#classmethod
def tiles_to_pixels(cls, tile):
return cls(tile._x * tile.side_length, tile._y * tile.side_length)
#classmethod
def tiles_to_tiles(cls, tile):
return cls(tile._x, tile._y)
class Tile(object):
def __init__(self, x, y, side_length):
"""A tile object in a map"""
self._x = x # x-coord in tiles
self._y = y # y-coord in tiles
self.side_length = side_length # pixels per tile
#property
def in_pixels(self):
"""self.in_pixels returns an object whose .x and .y
correspond to the x and y position IN PIXELS of the
top-left corner of the tile."""
_tile = _Tile.tiles_to_pixels(self)
return _tile
#property
def in_tiles(self):
"""self.in_tiles returns an object whose .x and .y
correspond to the x and y position IN TILES of the
top-left corner of the tile."""
_tile = _Tile.tiles_to_tiles(self)
return _tile
def change_side_length(self, new_length):
"""Use to change the side length. This can break
your whole map since it's naive, so be careful."""
self.side_length = new_length
my_tile = Tile(0,0,32) # 32 pixel tile starting at (0,0)
my_tile.x # NameError, since it's called my_tile._x
my_tile.in_tiles.x # 0
my_tile.in_pixels.y # 0
other_tile = Tile(4,7,32) # 32 pixel tile starting at (4,7)
other_tile.y # NameError, see above
other_tile.in_tiles.y # 7
other_tile.in_pixels.x # 128
I'm using Livewires and pygame and one of my objects in the game that gives you extra lives is being mistaken as an asteroid object, and when the extra lives objects collides with the player it returns the 'Extra lives object has no attribute handle_caught' error message, so can I please have some help.
class Extralives(games.Sprite):
global lives
image = games.load_image('lives.png', transparent = True)
speed = 2
def __init__(self,x,y = 10):
""" Initialize a asteroid object. """
super(Extralives, self).__init__(image = Extralives.image,
x = x, y = y,
dy = Extralives.speed)
def update(self):
""" Check if bottom edge has reached screen bottom. """
if self.bottom>games.screen.height:
self.destroy()
self.add_extralives
def add_extralives(self):
lives+=1
The asteroid class:
class Asteroid(games.Sprite):
global lives
global score
"""
A asteroid which falls through space.
"""
image = games.load_image("asteroid_med.bmp")
speed = 1.7
def __init__(self, x,image, y = 10):
""" Initialize a asteroid object. """
super(Asteroid, self).__init__(image = image,
x = x, y = y,
dy = Asteroid.speed)
def update(self):
""" Check if bottom edge has reached screen bottom. """
if self.bottom>games.screen.height:
self.destroy()
score.value+=10
def handle_caught(self):
if lives.value>0:
lives.value-=1
self.destroy_asteroid()
if lives.value <= 0:
self.destroy_asteroid()
self.end_game()
def destroy_asteroid(self):
self.destroy()
part of the player class which handles the collisions:
def update(self):
""" uses A and D keys to move the ship """
if games.keyboard.is_pressed(games.K_a):
self.x-=4
if games.keyboard.is_pressed(games.K_d):
self.x+=4
if self.left < 0:
self.left = 0
if self.right > games.screen.width:
self.right = games.screen.width
self.check_collison()
def ship_destroy(self):
self.destroy()
def check_collison(self):
""" Check if catch pizzas. """
global lives
for asteroid in self.overlapping_sprites:
asteroid.handle_caught()
if lives.value <=0:
self.ship_destroy()
for extralives in self.overlapping_sprites:
extralives.add_extralives()
Here is your problem:
for asteroid in self.overlapping_sprites:
asteroid.handle_caught()
if lives.value <=0:
self.ship_destroy()
The fact that you call your loop variable asteroid does not mean that it's magically only going to ever be an asteroid. Not if you have other kinds of objects you can collide with! overlapping_sprites is all overlapping sprites, not just asteroids. At some point asteroid is an ExtraLives object. When you try to call handle_caught() on it, this obviously fails because ExtraLives doesn't have a handle_caught() method.
The simplest solution here is to rename add_extralives to handle_caught on your ExtraLives class. After all, you're doing the same thing: handling the situation where you collide with (or "catch") the object, it's just a different kind of object so the result needs to be different, which you specify by providing different code. Being able to implement entirely different kinds of behavior by calling the same methods (called "polymorphism") is kinda the whole point of object-oriented programming.
The following loop has a similar problem, in that you're calling add_extralives() on objects that might not be of type ExtraLives. Fortunately you can remove this code since you're already handling this situation by renaming add_extralives to handle_caught.
for extralives in self.overlapping_sprites:
extralives.add_extralives()
I am trying to do an animation of a Particle Swarm Optimization using Python and Mayavi2.
The animation is working fine, my problem is that it is not possible to interact with the plot while it is animating the movement. Specifically i would like to turn the graph and zoom. Maybe someone has experience doing animations?
The way i do it is first to calculate the positions of the particles and then to store them. After the calculation is finished i plot the positions of the particle at the first instace of time with point3d() and then i iterate through time updating the data using the set() method.
Is there a way to make it possible to turn the graph? I have heard about something with threads, disabeling the the rendering, but i could not figure out how to do it in my code. Besides lots of other stuff, I have read:
http://code.enthought.com/projects/mayavi//docs/development/html/mayavi/mlab_animating.html
http://code.enthought.com/projects/mayavi//docs/development/html/mayavi/tips.html#acceleration-mayavi-scripts
but it can't see how to use it.
Any suggestions?
Here is my code:
#!/usr/bin/env python
'''
#author rt
'''
import pylab as plt
from numpy import *
from mayavi import mlab
from threading import Thread # making plotting faster?
import ackley as ac
class Swarm(Thread, object):
'''
constructor for the swarm
initializes all instance variables
'''
def __init__(self,objective_function):
Thread.__init__(self)
# optimization options
self.omega = 0.9 # inertial constant
self.c1 = 0.06 # cognitive/private constant
self.c2 = 0.06 # social constant
self.objective = objective_function # function object
self.max_iteration = 100 # maximal number of iterations
# Swarm stuff
self.number = 0
self.best = [] # gbest; the global best position
self.particles = [] # empty list for particles
# temporary
self.min = self.objective.min
self.max = self.objective.max
self.best_evolution = []
# self.dimensions = 2 # dimensions NB!
'''
add particles to the swarm
find the best position of particle in swarm to set global best
'''
def add_particles(self, n):
for i in range(n):
particle = Particle(self)
if i == 0: # initialize self.best
self.best = particle.position
if particle.eval() < self._eval(): # check if there is a better and if, set it
self.best = copy(particle.position)
self.particles.append(particle) # append the particle to the swarm
def _eval(self):
return self.objective.evaluate(self.best)
def plot(self):
for i in range(self.max_iteration):
pos_x = []
pos_y = []
pos_z = []
#print pos_x
for particle in self.particles:
[x,y,z] = particle.trail[i]
pos_x.append(x)
pos_y.append(y)
pos_z.append(z)
#print pos_x
if i ==0:
g = mlab.points3d(pos_x, pos_y,pos_z, scale_factor=0.5)
ms =g.mlab_source
ms.anti_aliasing_frames = 0
ms.set(x=pos_x, y = pos_y, z = pos_z,scale_factor=0.5) #updating y value
#print pos_y
#ms.set(x=pos_x) # update x values
#ms.set(y=pos_y) #updating y value
#ms.set(z=pos_z) #updating y value
#for p in self.particles:
#p.plot()
def plot_objective(self):
delta = 0.1
v = mgrid[self.min:self.max:delta,self.min:self.max:delta]
z = self.objective.evaluate(v)
#mlab.mesh(v[0],v[1],z)
mlab.surf(v[0],v[1],z) # surf creates a more efficient data structure than mesh
mlab.xlabel('x-axis', object=None)
mlab.ylabel('y-axis', object=None)
mlab.zlabel('z-axis', object=None)
def _info(self):
self.plot()
print '----------------------------'
print 'The best result is:'
print 'Coordinates:', self.best
print 'Value: ', self._eval()
#print 'with ', nreval, 'evaluations'
print 'nr of particles: ', len(self.particles)
print '----------------------------'
def run(self):
self.plot_objective()
self.best = self.particles[0].get_position()
iteration = 0
while iteration < self.max_iteration:
#if iteration!= 0: obj.scene.disable_render = True
#disable_render = True
for particle in self.particles:
rnd_c1 = array([random.uniform(0,1),random.uniform(0,1)])
rnd_c2 = array([random.uniform(0,1),random.uniform(0,1)])
particle.velocity = self.omega * array(particle.velocity) + \
self.c1 * rnd_c1 * (array(particle.best) - array(particle.position)) + \
self.c2 * rnd_c2 * (array(self.best) - array(particle.position)) # TODO: change so independent rnd for components
particle.position = array(particle.position) + particle.velocity
if particle.eval() < particle.best_eval():
particle.best = copy(particle.position)
if particle.eval() < self._eval():
self.best = copy(particle.position)
particle.update() # add the point to the trail
iteration +=1
self.best_evolution.append(self._eval())
#obj.scene.disable_render = False
print 'finished: ', iteration
self._info()
'''
Class modeling particle
'''
class Particle():
def __init__(self, swarm):
self.swarm = swarm
x_rand = random.uniform(self.swarm.min,self.swarm.max)
y_rand = random.uniform(self.swarm.min,self.swarm.max)
self.position = array([x_rand,y_rand])
v_x_rand = random.uniform(self.swarm.min,self.swarm.max)
v_y_rand = random.uniform(self.swarm.min,self.swarm.max)
self.velocity = array([v_x_rand, v_y_rand])
self.size = 0.5
self.best = self.position
# visualization
self.trail = []
def plot(self):
[x,y] = self.position
z = self.eval()
mlab.points3d(x,y,z,scale_factor=self.size)
def eval(self):
return self.swarm.objective.evaluate(self.position)
def best_eval(self):
return self.swarm.objective.evaluate(self.best)
def get_position(self):
return self.position
def update(self):
[x,y] = self.position
z = self.eval()
#print [x,y,z]
self.trail.append([x,y,z])
def plot_trail(self,index):
[x,y,z] = self.trail[index]
mlab.points3d(x,y,z,scale_factor=self.size)
# Make the animation
mlab.figure(1, bgcolor=(0, 0, 0), size=(1300, 700)) # create a new figure with black background and size 1300x700
objective = ac.Ackley() # make an objective function
swarm = pso.Swarm(objective) # create a swarm
nr_of_particles = 25 # nr of particles in swarm
swarm.add_particles(nr_of_particles)
swarm.run()
#swarm.start()
mlab.show()
print '------------------------------------------------------'
print 'Particle Swarm Optimization'
#objective.info()
print 'Objective function to minimize has dimension = ', objective.get_dimension()
print '# of iterations = ', 1000
print '# of particles in swarm = ', nr_of_particles
print '------------------------------------------------------'
In my case, even though I was somewhat able to do what Brandon Rhodes suggested for a mock program (https://stackoverflow.com/questions/16617814/interacting-with-mlab-scene-while-it-is-being-drawn), I could not manage to convert my already existing larger program.
Then I found this link: http://wiki.wxpython.org/LongRunningTasks
So, I just sprinkled a lot of wx.Yield() s inside my loops. This way I did not need to change my program structure, and I am able to interact with the window. I think better ways are explained in the link.
Your problem is that the wx event loop, which runs the Mayavi GUI window and listens for mouse clicking and dragging and responds by moving the scene, is not getting any time to run during your animation because you are keeping Python captive in your loop without ever letting it return control.
Instead of keeping control of the program with a loop of your own, you need to create a wx.Timer class that advances the scene by one frame update, and that then returns control to the wx event loop after scheduling itself again. It will look something like this:
import wx
...
class Animator(wx.Timer):
def Notify(self):
"""When a wx.Timer goes off, it calls its Notify() method."""
if (...the animation is complete...):
return
# Otherwise, update all necessary data to advance one step
# in the animation; you might need to keep a counter or
# other state as an instance variable on `self`
# [DATA UPDATE GOES HERE]
# Schedule ourselves again, giving the wx event loop time to
# process any pending mouse motion.
self.Start(0, oneShot=True) # "in zero milliseconds, call me again!"
I played with slightly higher values like 1 for the number of milliseconds that wx gets to run the UI with, but could not really tell a difference between that and just choosing 0 and having control returned "immediately".