Random movement pygame

Question

I\'m trying to make a simple life simulator, and I need the \"cells\" to move almost randomly (with a few rules) across the screen. But the problem is, after a while they tend t

Answer 1

The reason your cells are bunching up to the top-left is because of random.randrange().

The randrange() part handles the range, as per the python range() function. Looking at the range() function, range( A, B ) returns a list A -> B-1:

>>> for i in range( 1,10 ): print( i, end = ", " )
... 
1, 2, 3, 4, 5, 6, 7, 8, 9,

So when your code is doing random.randrange(directions[self.direction][0][0],directions[self.direction][0][1]), it's excluding the last item in the range, which looks to be "SE". Hence they're a little more likely to head in the other directions, and after thousands of iterations, that moves them to the top-left corner.

Answer 2

A lot of random number generators tend to favour smaller numbers. You may need to offset the random values by some other tiny random number, or look into more sophisticated generators.

I looked around quickly, and I couldn't find any "truly" random generators.

Try adding a tiny number to the other random numbers and see start happens.

Just to clarify what I meant:

#Instead of:

self.move[0] = random.randrange(directions[self.direction][0][0],directions[self.direction][0][1])
self.move[1] = random.randrange(directions[self.direction][1][0],directions[self.direction][1][1])

#Try something like:

smallOffset = random.random() #Random floating-point number between 0 and 1 ("Tiny number")

self.move[0] = random.randrange(directions[self.direction][0][0],directions[self.direction][0][1]) + smallOffset
self.move[1] = random.randrange(directions[self.direction][1][0],directions[self.direction][1][1]) + smallOffset

You may have to adjust smallOffset to limit how large it can get (because, it can be a value up to almost 1, which isn't really small anymore)