Random particle velocity -- with individual particle access (at long last) + (some extra stuff)

randomParticle.py

# random particle velocity -- with individual particle access (at long last)

import maya.cmds as cmds
import random

random.seed(1234)


amountOfParticles = 500
r = 10
vr = 4
myList = list()

#list particles and delete
# convenience

particleList = cmds.ls( 'particleObject*' )
#if there are any, then delete them all
if len(particleList) >= 1: 
    cmds.delete(particleList)
    print ('deleted old particleObject')
else:
    print ('no old particleObjects')


for i in range( 0, amountOfParticles):
    
    x = random.uniform(- r, r)
    y = random.uniform(- r, r)
    z = random.uniform(- r, r)
    newPosition = (x,y,z)
    myList.append(newPosition)
    
    
particleResult = cmds.particle(p=myList,n='particleObject#')

#set all particles to specific velocity
#cmds.setParticleAttr( 'particleObject*', at='velocity', vv=(1, 2, 3) )

#set all particles to random velocity between (-x,-y,-z) and (x,y,z)
#cmds.setParticleAttr( 'particleObject*Shape', at='velocity', rv=(2,2,2))

# doest seem to work
#cmds.select( 'particleObject*Shape.pt[0]')
#cmds.setParticleAttr( vv=(1, 2, 3), at='velocity' )
#cmds.setParticleAttr( 'particleObject*', at='velocity' )


#velExpString = 'if(particleId == %s) velocity = <<%s, %s, %s>>;' %(myParticleId, vx, vy, vz)
#print (velExpString)
#cmds.dynExpression( 'particleObject*Shape', s='velocity = <<rand(5), rand(5), rand(5)>>;', rbd=1 )
#cmds.dynExpression( 'particleObject*Shape', s='if(particleId == 1) velocity = <<0,1,0>>;', rbd=1 )



for myParticleId in range ( 0, amountOfParticles):
    vx = random.uniform(- vr, vr)
    vy = random.uniform(- vr, vr)
    vy = random.uniform(- vr, vr)
    velExpString = 'if(particleId == %s) velocity = <<%s, %s, %s>>;' %(myParticleId, vx, vy, vz)
    print (velExpString)
    cmds.dynExpression( 'particleObject*Shape', s=velExpString, rbd=1 )

Just kidding, this only seems to work the first time you press play (WHY???)